Digital PDFs

EK-0TU80-UG-2

January 1983

100 pages

Original

3.7MB

Document:	TU80 Subsystem User Guide
Order Number:	EK-0TU80-UG
Revision:	2
Pages:	100
Original Filename:

OCR Text

EK-OTU80- UG-002

TUBO
Subsystem
User Guide

EK-OTU80- UG-002

TUBO
Subsystem
User Guide

Prepared by Educational Services
of
Digital Equipment Corporation

1 st Edition, January 1983
2nd Edition, October 1983
Copyright © 1983 by Digital Equipment Corporation All Rights Reserved
Printed in U. S. A
The reproduction of this material, in part or whole, is strictly prohibited For copy
information, contact the Educational Services Department, Digital Equipment
Corporation, Maynard, Massachusetts 01754.
The information in this document is subject to change without notice. Digital Equipment
Corporation assumes no responsibility for any errors that may appear in this document
The following are trademarks of Digital Equipment Corporation, Maynard, Massachusetts.

~DmDDmD
DEC
DECsystem-10
DECSYSTEM-20
DECUS
DECmate
DECnet

DECwriter
DIBOL
LA
MASSBUS
PDP

P/OS
Professional
Rainbow

RSTS
RSX
UNIBUS
VAX
VMS
VT
Work Processor

CONTENTS

PREFACE
CHAPTER 1

INTRODUCTION

General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-1
TU8a Basic Features ........................................................... 1-1
Tape Media Requirements ....................................................... 1-2
TU8a Variations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-2
Related Documents ............................................................ 1-3
TU8a Speed Modes and Speed Selection ............................................ 1-3
System Overview .............................................................. 1-5
Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-7
TU8a UNIBUS Adapter Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-8
Transport Physical Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-9
Tape Deck ............................................................... 1-9
Reel Motors and Hubs .................................................. 1-9
Power Amplifier Module ............................................... 1-11
Air Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-1 1
Magnetic Head Assembly ................... . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-11
Tape Cleaner ........................................................ 1-11
BOT/EOT Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-11
File Protect Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-11
Power Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-11
Cover Interlock ...................................................... 1-11
Electronic Logic Cage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-11
Pneumatic Pump/Air Filter ..................................................... 1-11
Power Supply and Cooling Fan .................................................. 1-11
Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-11

CHAPTER 2

OPERATING INSTRUCTIONS

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Operator Controls .........................................................
Diagnostic Controls ........................................................
Operator's Hints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Operating Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Inserting Write-Enable Ring .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Tape Threading and Loading .................................................

iii

2-1
2-1
2-2
2-3
2-3
2-3
2-3
2-4

Tape Unloading ...........................................................
Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
On-Line Mode ........................................................
Operator Corrective Actions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

CHAPTER 3

CUSTOMER DIAGNOSTICS

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Operator Troubleshooting .......................................................
Error Reporting .. ".. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Operator Diagnostic Procedure ..................... ". . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Operator Diagnostic Tests ...................................................
Test 01 .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Test 02 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Test 03 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

CHAPTER 4

3-1
3-1
3-2
3-2
3-2
3-2
3-4
3-4

CARE AND PREVENTIVE MAINTENANCE

Customer Responsibilities .......................................................
Care of Magnetic Tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Tape Transport Customer Maintenance .............................................
. Magnetic Tape Transport Cleaning Kit .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Reflective Tape Markers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Transport Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Magnetic Heads .......................................................
EOT/BOT Sensor and Tape Cleaner. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Air Bearings .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Top Cover, Tape Deck, and Head Assembly Dust Covers . . . . . . . . . . . . . . . . . . . . . . ..
Accessories and Supplies ........................................................
Ordering .................. : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

CHAPTER 5

2-6
2-6
2-6
2-6

4-1
4-1
4-2
4-2
4-3
4-4
4-4
4-4
4-5
4-5
4-5
4-5

PROGRAMMING

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-1
TU80 Performance Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-1
Speed Modes and Speed Selection ............................................. 5-1
Performance Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-3
TU80 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-3
TSBA ................................................................... 5-3
TSDB ................................................................... 5-5
NormalOperation ..................................................... 5-5
TSSR ................................................................... 5-6
XST ....................................................... . . . . . . . . . . . .. 5-8
TU80 Register Summary .................................................... 5-8
Packet Processing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-13
Command Packet/Header Word .............................................. 5-16
Command Packet Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-18
Get Status Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-20
Read Command ...................................................... 5-20
Write Characteristics Command .......................................... 5-20
Write Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-23

Position Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-23
Format Command ............................................................ 5-24
Control Command .......... " . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-24
Initialize Command ........................................................... 5-24
Message Packet/Header Word ...................................................... 5-26
Message Packet Example ........................................................... 5-27
Operational Information ................................................................. 5-27
UNIBUS Registers ................................................................ 5-27
Command and Message Packets ..................................................... 5-28
Special Conditions and Errors ....................................................... 5-28
Status Error Handling Notes ........................................................ 5-29
M7454 Failure .................................................................... 5-29
Operational Differences ................................................................. 5-30

CHAPTER 6

INSTALLATION

Site Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-1
Space Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-1
Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-1
Environmental Requirements and Limits .............................................. 6-2
Tools Required .................................................................... 6-2
Unpacking and Inspection ............................................................... 6-2
Floor Loading and Routing. . . . . . . .. . . .. . . . . . . ... ..... . . . . . .. .. . . . . .. . . . . . . .. ..... . .. 6-2
Unpacking. . . . . . . . . . . . . . .. . . . . . . . . . . .. . . . . . .. .. . . . . .. .. .. .. . . . . . .. . .. .. . . .. . .. .. .. 6-2
Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-5
Operation Preparations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-5
Mechanical Installation ............................................................. 6-5
Electrical Connection .............................................................. 6-11
Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-12
UNIBUS Adapter Module Installation and Interface Cabling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-12
Turnkey Configuration ............................................................. 6-12
TU80 External Cabling ............................................................ 6-14
Add-On Configuration ............................................................. 6-15
M7 454 Preparation and Installation ............................................. 6-15
CPU Internal Cabling ......................................................... 6-17
TU80 Acceptance Diagnostics ........................................................... 6-20
Power-On Health Check ............................................................ 6-21
Basic Operator Diagnostic Test 01 ................................................... 6-21
UNIBUS Adapter Module Resident Diagnostic ..... , .................................. 6-21
M7454 Status Checking ....................................................... 6-21
PDP-II Based Remote Diagnostics .................................................. 6-22
PDP-II Front--End Diagnostics CZTUW, CZTUX, CZTUY, CZTUZ .............. 6-22
PDP-II Data Reliability Diagnostic ............................................. 6-23
Operating Instructions for PDP-II Based Diagnostics .................................. 6-23
Hardware Parameters .......................................................... 6-24
Software Parameters ,.......................................................... 6-24
VAX- Based Remote Diagnostic ..................................................... 6-24
VAX Front-End Diagnostics ................................................... 6-24
VAX Data Reliability Diagnostic ............................................... 6-24
Operating Instructions for VAX-Based Diagnostics ..................................... 6-25

FIGURES
1-1
1-2
1-3
1-4
1-5
1-6
2-1
2-2
2-3
4-1
4-2
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
5-13
5-14
5-15
5-16
5-17
5-18
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
6-9
6-10
6-11
6-12
6-13
6-14
6-15
6-16

TU80 Tape Subsystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-3
TU80 Subsystem Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-5
TU80 Functional Diagram ..................................................... 1-8
UNIBUS Adapter Module M7454 ..... .......................... . ............... 1-9
Tape Deck Components ....................................................... 1-10
Major Transport Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-10
Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2-1
Write-Enable Ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2-4
Tape Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2-5
Reflective Tape Markers ....................................................... 4-3
Magnetic Head/Tape Path Components .......................................... 4-4
Data Buffering and TU80 Performance Upgrading. . . . . . .... . .. . . . . .. . . . . . . . . . . . . .. 5-2
TSBA Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-4
TSDB Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-5
TSSR Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-6
TU80 Register Summary ....................................................... 5-8
Command Packet Header Word ................................................ 5-16
Byte Swap Sequence, Forward Tape Direction ........ " .......................... 5-18
Byte Swap Sequence, Reverse Tape Direction .................................... 5-19
Get Status Command Packet Example ........................................... 5-20
Read Command Packet Example ................................................ 5-21
Write Characteristics Command Packet Example .................................. 5-21
Write Command Packet Example ............................................... 5-23
Position Command Packet Example ............................................. 5-23
Format Command Packet Example .............................................. 5-25
Control Command Packet Example .............................................. 5-25
Initialize Command Packet Example ............................................. 5-25
Message Packet First Header Word ............................................. 5-26
Message Packet Example ...................................................... 5-27
TU80 Space Requirements ..................................................... 6-1
Unpacking a Transport. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-3
Removing a Transport from a Skid Using the Supplied Ramps. . . . . . .. . . . . . . . . . . .. . .. 6-4
Reversing the Rear Shipping Bracket ................ . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-6
Cabinet Leveler Feet Assembly and Extension Stabilizer ........................... 6-7
Leveler Feet Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-8
Cabinet Assembly ............................................................. 6-9
Rear Stabilizer Installation ..................................................... 6-10
874 Power Controller .......................................................... 6-11
Typical Interface Cabling ...................................................... 6-13
Plug-to-Plug Connections of I/O Cables .......................................... 6-13
Installation of External Cables in TU80 Tape Deck ............................... 6-14
UNIBUS Adapter Module and I/O Internal Cables ................................ 6-16
DIP Switchpack Setting for a Single TU80 Configuration ........................... 6-16
TU80 Interface Cabling Flowchart .............................................. 6-18
1/ 0 Bulkhead Connector Panel and Frame ....................................... 6-19

TABLES
1-1
1-2
2-1
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
5-13
6-1
6-2

Related Documents .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1-4
Specifications ................................................................. 1-5
Operator Corrective Actions .................................................... 2-7
TSBA Bit Definitions .......................................................... 5-4
TSDB Bit Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-5
TSSR Bit Definitions .......................................................... 5-7
RB PCR Bit Definitions ........................................................ 5-9
XSTATO Bit Definitions ....................................................... 5-9
XSTATI Bit Definitions ....................................................... 5-11
XSTATI Bit Definitions ........................ , .............................. 5-12
XSTAT3 Bit Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-13
Command Packet Header Word Bit Definitions ................................... 5-16
Command Code and Mode Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-1 7
Write Characteristics Data Bit Definitions ........................................ 5-22
Message Packet First Header Word Bit Definitions .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-26
Termination Class Codes ...................................................... 5-28
Single-TU80 Address Selection .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-1 7
Address Selection in Multi-TU80 Configuration ................................... 6-17

vii

111111111111\1\11\ 1111111111111111111111111111

MA-O"O-82

PREFACE

The TU80 Subsystem User Guide provides all information necessary to install, accept, and operate the
TU80 Magtape Tape Subsystem.
The manual is divided into six chapters.

Chapter 1 gives the general functional and physical transport description, system overview, and basic
specifications.
Chapter 2 describes all operator controls and indicators and gives instructions for routine, fault-free transport operation. It also provides fault codes and operator corrective actions to be taken in the event of transport failure.

Chapter 3 provides troubleshooting information and customer diagnostics (tests, fault codes, and operator
actions).

Chapter 4 provides complete care/preventive maintenance (PM) information including customer responsibilities, magnetic tape care, and customer PM procedures, accessories and supplies.

Chapter 5 describes TU80 programming concepts, registers, and data processing flow.
Chapter 6 provides complete unpacking and installation information including power and signal cabling
and acceptance test procedures.

CHAPTER 1
INTRODUCTION

GENERAL
The TU80 Magnetic Tape Subsystem is a low-cost, dual-speed 9-track tape data storage system. It features
microprocessor-based electronic control systems and streaming techniques for high data transfer rates, data
reliability, and maintainability.
The horizontally-mounted TU80 Tape Transport is a fully integrated tape storage system. It is packaged
with its formatter and power controller in a standard 40-inch high H9643 cabinet. The TU80 writes and
reads data in ANSI-compatible phase-encoded (PE) 9-track 1600-bit/inch format. The tape speed is 25
in/s (63.5 cm/s) in Start/Stop mode and 25 in/s (63.5 cm/s) or 100 in/s (254 cm/s) in Streaming mode.
The TU80 Subsystem consists of the standalone tape transport and a UNIBUS adapter module. This module is designed for UNIBUS-equipped PDP-II and VAX processors. It plugs into a host computer's
UNIBUS small peripheral controller (SPC) slot and provides communication with the corresponding tape
transport.
NOTE
The TU80 cabinet may hold an optional disk drive
mounted under the tape transport at the bottom of
the cabinet. Consult the User Guide of the appropriate disk drive for user information.
The TU80 can operate either as a conventional, low-speed, start/stop tape transport, or as a high-speed
streaming tape unit.
The TU80 does not have a capstan, tension arms, or vacuum columns in its tape drive mechanism. Instead,
the TU80 uses a microprocessor-controlled servo that directly controls the motors to maintain a constant
tape speed and tension.
TU80 BASIC FEATURES
The following are some features of the TU80.
•

Short tape path

•

No capstan, no moving parts in the tape path

•

Tape contacts only the tape cleaner and magnetic head

•

Air bearings and solid-state tape tension sensor

1-1

•

Microprocessor control of all main operating functions

•

Built-in diagnostics automatically initiated during power-on sequence and manually initiated by
an operator or customer engineer from the front control panel

•

Resident adaptive speed control

•

No mechanical or electronic adjustments

•

No scheduled preventive maintenance

•

Long-life magnetic head

nufaq
. . . . .. . . .. •. ·.;··~~t~i'~#:l{~
~~ch·ptB4tibi$.riWtst·iri
. ,::.: ......;.: :{. ... -... :;:.,::::.:.: ..... :: ..:. :'.::' .u(t~ilie:tapem~~ia:~b'lt~'~it~'

,::~ :.~:.:,:.

::>~

e~icta~.as.s~t.in.~~ric~n •. Natiop~l StaIl9~r~~.Illstit~te'(AN~n·s~~m4ar? .X3.. 54.J~76:· . ~~s·(jesigIl

i~s • th~t.tbe '~agIletk ta.pes ·llse~ollt~i~tape(jrivt!~trictly.,adhel'e to>ANSI$~afld,(lr(l· :X3.40~198L
:fdfrbisstalldard .defines the '. minimum .physi~alandmagnetic· req~irementsfor .·1/2inchwide.magnetic
;~(tape. ·.In·addition ·.to.· meeting .ANSI'requirements,allDIGITAL recommended tapes . mustJ~onfortn to
;jDIGITAL' s ownIUagnetic tapespecificatiotls.This~pecific.ati()nis used in th<?evaluationand qua.lifica~
\:tionofmagnetictapes for DIGITAL~ suse,an(jsaJe toitscusttJlllers;
, , ,
;

'nDIOl'T~LisC()nstantly evalu~tingtapemediajnan ongoing effort toeIl$ure a high qualityptoduct.To
. ::t~e,therearen() back~c()ated.· magnetic . tapes that Il1eetpI{}ITAL'~ . specfication. Back-.coating'.' bas
e.en found to calIse such prqblemsastapeslippage;auto-Ioadfailures, falseEOT (End Of Tape)ang
OT(Begjllllin~'9f~ape) sensing and more freqpent drivecIea~ing.due to the·residue:left.on·thetape'
.~e;byt~ba:k:o~til,lg.As .a'result of these problems,back~coated magnetic tapes are notrecol1l""'
4tdf~1~se~ll'i;~~e~~O ·~~.·driyeT
t.L~:

,~,,: : . .

/.( ..., ,i.>·:: . ~ . . :. : ... ,'.: .. ' ..;.

:.~.

',mwp~liabilityo~tne'TiU8(ftape' dri¥e,·.·()nly, tbose.~gne~'
,~t~~

. . . . . . . ,,
,~

·aI{j'$hould:~.:·~'.

NOTE
ANSI standards can be obtained through:
American National Standards Institute
1430 Broadway Street
New York, New York 10018
(212) 354-3300.
TU80 VARIATIONS
The following are two variations of the TU80.
TU80-AA
120 Vac, 60 Hz

TU80-AB
220/240 Vac, 50 Hz

Figure 1-1 shows the TU80 and its major components.

1-2

. ., ...,............. '.

TU80TAPE
TRANSPORT

1111\1\1\ \1\ 1\ 1111 \
"'"11 111 111111\1111

MA-0077-82

Figure I-I

TU80 Tape Subsystem

RELATED DOCUMENTS
The documents listed in Table 1-1 are applicable to the TU80 and are available through the local
DIGITAL Sales and Service Office or the Accessories and Supplies Group. Refer to the Ordering section
in Chapter 4 for details.
Also, use applicable manuals and handbooks for the appropriate PDP-II or VAX computer systems and
processors, and RA80, RA8I, and RA60 disk drives.
TU80 SPEED MODES AND SPEED SELECTION
The TU80 operates at one of three speeds. Speed is selected automatically by the TU80 to optimize data
throughput.
•
•
•

25 in/s start/stop
25 in/s streaming
100 in/s streaming

In the 25 in/s start/stop speed, the TU80 can stop and start within an ANSI minimum interblock gap of 0.6
inches when reading. A stop or a start in this mode is similar to operation of a "conventional" (nonstreaming) tape transport.

1-3

Table 1-1

Related Documents

TU80 Subsystem User
Guide

EK-OTU80-UG

Contains the functional
overview, installation,
operating, and programming
information

TU80 Pocket Service
Guide

EK-OTU80-PS

Provides a quick reference
to maintenance and repair
procedures for the trained
trained service personnel

TU80 Technical!
Service Manual

EK-OTU80-TM

Contains the system
functional description,
installation, and
acceptance procedures,
theory of operation
maintenance information

TU80 Pathfinder

EK-OTU80-SV

Contains test documentation
(troubleshooting procedures,
diagnostic tests, fault
codes and sub-fault codes)
for use by trained service
personnel

TU80 Illustrated
Parts Breakdown

EK-OTU80-IP

Provides a listing and
illustrations of TU80
assemblies and replaceable
parts

874 Power Controller
IPB

EK-00874-IP

TU80 Field Maintenance
Print Set

MP01603

Contains unit assemblies,
circuit schematics, revision
matrix, and transport
interconnect drawings for the
TU80 subsystem.

In the 25 in/s or 100 in/s streaming speeds, the TU80 always writes ANSI minimum gaps of 0.6 inches, but
is operating as a "streaming tape" transport. When streaming, the TU80 cannot start and stop in the interblock gap (IBG), as conventional tape drives do. When a streaming drive does have to stop, the TU80 does the
following.
•

Slowly moves forward to a stop.

•
•

Backs up over a section of tape previously processed.
Awaits the next command.

•

Accelerates, taking a running start so that when it encounters the original IBG, it is at full speed.

This cycle is called repositioning. An entire repositioning cycle takes approximately 0.2 seconds at 25 inls
and 0.7 seconds at 100 in/s to complete. If the CPU is not capable of supplying data to, or accepting data
from, a streaming tape drive at a rate that keeps the drive constantly in motion (streaming), then the drive
repositions when it runs out of commands to execute. This results in very long repositioning time and poor
data throughput.

1-4

The TU80's microprocessor-based adaptive speed control system automatically changes the TU80 speed
from 100 in/s streaming to 25 in/s streaming if excessive repositioning is sensed. Conversely, if the TU80
has been successfully streaming at 25 in/s for a determined time period, the adaptive speed control changes
the speed to 100 in/so A similar algorithm controls speed changing from 25 in/s start/stop to 25 in/s
streaming, and vice versa.
For more information on TU80 programming and performance, refer to Chapter 5 - Programming.
SYSTEM OVERVIEW
Figure 1-2 shows the TU80 subsystem block diagram. The subsystem consists of one tape transport, one
UNIBUS adapter module, and an interface cabling set.
Table 1-2 gives the basic operating specifications for the TU80 magtape subsystem.

TAPE TRANSPORT

ADAPTER
MODULE

INTERFACE
CABLE
ASSEMBLY
FORMATTER

DRIVE

TUBO SUBSYSTEM

CPU

MA-0078-82

Figure 1-2

TU80 Subsystem Block Diagram

Table 1-2 Specifications
Functional Characteristics
Tape speed (nominal)
Low speed start/stop mode
Low speed streaming mode
High speed streaming mode

25 in/s
25 in/s
100 in/s

Tape capacity (maximum)

40 Mbytes

Data transfer rate (burst)
Low speed modes
High speed streaming mode

40 Kbyte/s
160 Kbyte/s

Data format/recording

9 track, phase-encoding,
1600 bit/inch

Rewind time (nominal)
Load time (maximum)

2.5 minutes
15 seconds

1-5

Table 1-2 Specifications (Cont)
Physical Characteristics
Electronics

Solid-state

Tape width
Tape thickness
Tape tension

12.65 mm (0.5 in)
38.1 micron (1.5 mil)
2.23 N (8 oz)

Reel diameter
Reel capacity

26.7 cm* (10.5 in)
732 m* (2400 ft)

Transport dimensions

105.7 cm (H) x 54.6 cm (W) x 76.2 cm (D)
41.6 in (H) x 21.5 in (W) x 30 in (D)

Transport weight (in cabinet)

127 kg (280 lbs)

UNIBUS adapter

Standard quad-size module

Power requirement

4 A at +5 Vdc

Operational Characteristics
Power requirements
Voltage

93-128 Vac, 120 Vac nominal,
60 Hz, single phase
187-256 Vac, 220 or 240 Vac
nominal, 50 Hz, single phase

Current

Average input current 2.0 Arms
at 100 in/s

Power consumption

300 VA - Standby and loaded
550 V A max - Start/stop

Power controller

Model 874B, 50 Hz, 240 V, 12 A
Mode1874D, 60 Hz, 120 V, 24 A

Power cord

3 wire number 12 A WG 16 ft long;
plug - NEMA 6-15P (50 Hz)
NEMA 5-30 (60 Hz)

Operating temperaturet
Storage temperature

10° C (50° F) to 40° C ( 104° F):j:
-10° C (14°F) to 50° C (122° F)

Relative humidity

20% to 80% (10% to 90% in storage)

* Smaller tape reels are also allowed.
t Restricted by the operating temperature of the media.
t Operating temperature will be limited by the temperature limitations of the media.

1-6

Table 1-2 Specifications (Cont)
Altitude

Up to 3048 m (10,000 ft) or
688 millibar (9.98 psi)

Heat dissipation (average)

1024 BTU/hr

Acoustical noise

51 dba for open office environment

Data Reliability
Recoverable write error

1 in 108 bits

Recoverable read-forward
error

1 in 109 bits

Recoverable read-reverse
error

1 in 108 bits

Unrecoverable read error

1 in 1010

Unrecoverable write error

Not allowed

Functional Description
The tape transport is interfaced to the host Central Processing Unit (CPU) via the UNIBUS adapter module. This module is plugged into a UNIBUS I/O slot in the CPU. The module processes data using the
packet processing protocol as described in Chapter 5. The adapter module-to-transport communication link
is accomplished via the interface cable assembly which connects the adapter module to the TU80 control
system.
The tape transport control system (Figure 1-3) consists of two logic modules and a power amplifier module. The two logic modules are functionally partitioned and each module contains a microprocessor for
control of all module functions.
First is the formatter/control module. It provides high-speed data interchange between the transport and
the host system including such functions as data fetching and formatting, and read/write operation. It also
handles single-track "on-the-fly" data error correction and initiates and monitors the built-in diagnostic
routines.
The second logic module is the Read/Write/Servo module. This module controls the tape drive electromechanical operation.
The third module is the power amplifier. This module receives low voltage analog signals from the logic
modules and outputs higher voltages to the reel motors.
The transport logic is compactly mounted in a metal cage under the tape deck.
The power supply, mounted at the rear of the tape deck, provides all required ac/dc voltages to the transport modules and mechanisms.

1-7

UNIBUS
ADAPTER
MODULE

----I....TAPE
TRANSPORT
I
I
I

OPERATOR
CONTROL
PANEL

I
I

I
~-

-----4

I
I
I
I

I
I
POWER
AMPLIFIER
MODULE

-I
~--------

.120/240- - .

I
L_

POWER
SUPPL Y
MODULE

MECHANICAL

I
I
I
r-..l.--

PNEUMATIC
PUMP/FILTER

I
I
I
I
I
...J

CONTROL
POWER

.,
I

VAC

INTERFACE CABLES

•
-

- - - ....
••••••
MA·QQ79·82

Figure 1-3

TU80 Functional Diagram

TU80 UNIBUS Adapter Module (M7454) - The UNIBUS adapter module (Figure 1-4) provides a functional interface between the transport and PDP-lIlY AX computers. The M7454 controls command decoding,
data fetchings and storing, and data transmission to and from the transport.
The quad-size M7454 module plugs directly into any small peripheral controller (SPC) slot in the UNIBUS
backplane of the DIGITAL host CPU. A set of the internal (ribbon) and external (shielded) cables connect the
adapter module to the tape transport. The standard external interface cable length is 3.66 m (12 ft). Effective
external cabling length is 2.7 m (9 ft). Longer external cables are needed for configurations' of three or four
tape drives on one CPU.
Each adapter module supports one tape transport. Maximum configuration is four TU80 transports radially
connected to a single CPU.

1-8

MA-OOBO-B2

Figure 1-4

UNIBUS Adapter Module M7454

TRANSPORT PHYSICAL DESCRIPTION
The TU80 is a manual load, reel-to-reel tape transport and includes the following major assemblies.
1.

Tape deck with Read/Write/Erase head, servo motors, air bearings and solid-state tension
sensors

Electronic control logic cage

Control panel

Pneumatic pump/air filter

Power supply and cooling fan

Tape Deck
The following is a brief description of the deck components and their functions (Figure 1-5 and 1-6).
Reel Motors and Hubs - The reel servo motors are mounted under the tape deck and are covered by an
acoustic, cooling and electrical cover. The servo motors drive the supply and take-up reels. The supply
(rear) hub has a manual, mechanical latch that secures the reel to the hub face by pressing the periphery of
the hub face while the reel is positioned against the bottom flange of the hub. The reel is released by
pressing the center button on the hub face.
The supply reel motor works in conjunction with the supply and take-up air bearings to control tape tension
across the recording surface of the magnetic head.
The take-up (front) reel is permanently mounted on the take-up motor shaft. The take-up motor/reel speed
is controlled to maintain constant tape velocity across the read/write head.

1-9

REAR (SUPPLY)
AIR BEARING,

BOT/EOT
BLOCK

REEL LATCH
(RELEASE)

ERASE HEAD
MAGNETIC
R/W HEAD

MACHINE TAKE-UP
REEL FIXED

FRON;~::~:~ Y.3

AIR BEARING
EDGE GUIDES &
PRESSURE SENSOR
TOP COVER
INTER LOCK

;,an
I..________~
__:_-_-_-_-_-_-___- ___-_-_-:..-:..-:..-:.."...!-- COVER LOCK
+

SWITCH

FRONT

Figure 1-5

MA-0081A-82

Tape Deck Components

AIR PUMP

AI4---=::-'-!.!..--':::'- REEL
MOTORS

ELECTRONIC _ _- - - - r r .
LOGIC
CAGE

AIR FILTER/
REGULATOR
MA-0082-82

Figure 1-6

Major Transport Assemblies

1-10

Power Amplifier Module - This module is also mounted under the tape deck within the motor acoustic
cover.
Air Bearings - Two air bearing/tension sensor assemblies are used to guide the tape across the magnetic
head on an air cushion and to measure air pressure reflection. The pressure signal is processed by the
TU80's control system that maintains constant tape velocity and air pressure by an appropriate change in
reel motor speed.
Magnetic Head Assembly - This assembly consists of a read/write head and an erase head.
The dual-gap read/write head unit is designed to perform the read/write functions in a 9-track format. The
dual-gap head allows a write-to-tape operation, read-only operation or read-after-write operation. A fullwidth erase head erases the tape during a write operation while it moves in forward direction before passing
over the write head.
Tape Cleaner - This cleaner consists of two blades and a vacuum port to strip unwanted particles off the
tape surface. The cleaner is designed so that one blade cleans tape in the forward direction and the second
cleans tape in reverse direction. The vacuum system directs the stripped particles through a screen and into
an air filter.
BOT/EOT Assembly - This assembly is adjacent to the magnetic head assembly. Beginning-of-tape (BOT)
and end-of-tape (EaT) markers are detected optically. Photosensors detect light reflected from BOT and
EaT markers on tape. An absence-of-tape (AOT) condition is detected when either one of the BOT and
EaT photosensors detects a reflective marker normally blocked by the presence of a tape.
File Protect Sensor - This sensor consists of a reflective ring around the supply hub and an adjacent photosensor that are used to detect the presence or absence of the write-enable ring on the supply reel.
Power Switch - The main power switch (circuit breaker) is at the rear right corner of the tape deck. In
OFF position (0 side pressed), input ac voltage is removed from the tape transport power supply. In ON
position (1 side is pressed), the transport is powered on.
Cover Interlock - The top cover interlock switch is a safety device that allows reel motion only when the top
cover is closed and latched.
Electronic Logic Cage
This metal cage, vertically mounted under the tape deck, is used as a security and mounting enclosure for
the formatter/control and read/write/servo modules. The external I/O cables are plugged into the connectors on the cage mounting plate.
Pneumatic Pump/Air Filter
The pump and air filter together with the plenums are a pressure/vacuum system. This system provides
specified air pressure/vacuum at the air bearings and the tape cleaner. The pneumatic system turns on and
operates continuously when the tape is loaded.
Power Supply and Cooling Fan
The power supply is mounted at the rear of the tape deck. The power supply provides ac/dc voltages when
the TU80 is powered on. A fan cools the power supply and provides air circulation for the TU80 logic
modules.
Control Panel
The TU80 control panel is in the upper right corner of the TU80 cabinet front panel. The control panel has
operational and diagnostic membrane-type switches, functional indicators, and 2-digit LED display.
(Chapter 2 details control panel functions).

1-11

CHAPTER 2
OPERATING INSTRUCTIONS

INTRODUCTION
This chapter explains the control panel and provides operating instructions for tape reel installation, and
loading and placing the TU80 on-line to the host computer.
CONTROL PANEL
Figure 2-1 shows the TU80 control panel switches and status indicators. These switches are all pushbutton
switches. Switch functions, and the conditions required for enabling the corresponding functions, are given
below.
The left part of the control panel contains operator switches and indicators. The 2-digit display indicates a
fault code related to an abnormal operating condition or a test code when in the diagnostic mode. The right
part of the panel contains the switches for diagnostic test procedures.

MAINTENANCE

"
0

FILE PRO

BOT

SELECT

~OGIC 1 I
OFF

INDICATOR

It-FO

PUSHBUTTDN~
ON

LOAD
REWIND

0
DIAGNOSTICS

~N 1 [(:1 OJ
1[~ESET J
[

LINE

I_I

TWO-DIGIT
LED
DISPLAY

[ UNLOAD

\..

c:Jc:J
[ EXECUTE

OPERATOR
MA-0083-82

Figure 2-1

Control Panel

2-1

Operator Controls
The following describes operator controls.
Switch!
Indicator
LOGIC OFF

Function
Switch - When pressed, power is removed from the transport logic and
LOGIC OFF indicator goes on.
Indicator - When on, LOGIC OFF indicates a standby power condition exists
(power supply is on, transport logic is off).
If the indicator is off and no other indicators are on, then power switch is set
off (0) or there is a power supply problem. If this indicator is off and LOGIC
ON indicator is on, all transport circuitry is in the power-on condition.

LOGIC ON

Switch - If LOGIC ON is pressed when the power switch is on 0), the transport logic and control system is powered up and the TU80 is ready for
operation.
Indicator - When on, LOGIC ON indicates the transport is powered up and
ready for use.

FILE PRO

Indicator - When on, FILE PRO indicates absence of a write-enable ring in
the supply reel and write operation is inhibited. Otherwise, write operations
are allowed.

BOT

Indicator - When on, BOT indicates the tape is positioned at the beginningof-tape (BOT) marker.

LOAD/REWIND

Switch - If the transport is powered on and tape is threaded, pressing this
switch causes a load operation to be performed. If tape is loaded, pressing the
switch causes a rewind operation to BOT.

UNLOAD

Switch - If tape is loaded at BOT, pressing this switch causes tape to unload
from the take-up reel and tape path onto the supply reel. If tape is loaded
beyond BOT, it rewinds to BOT and unloads tape onto the supply reel. If tape
is threaded, but not loaded, pressing the switch causes the transport to slowly
unload tape onto the supply reel.

ON-LINE

Switch - If tape is loaded, pressing this switch causes the transport to go online to the host system. Press the RESET switch to take the TU80 off-line.
Indicator - When on, ON-LINE indicates that the TU80 is ready for on-line
operation. All switches except RESET and LOGIC OFF are inhibited.

SELECT

Indicator - When on, indicates the following.

•

The address in TU80 and CPU are the same.

•

When the two 110 cables are disconnected, the address decoder in TU80
is functional.

•

Pin 1 in 110 cables and Pin 1 on the M7454 are assembled correctly.

•

TU80 is not in diagnostic mode.

2-2

RESET

Switch - When pressed, this switch places the transport off-line, stops tape
motion and clears error status. The switch can stop a LOAD or REWIND
operation. It also turns off the RESET indicator and clears diagnostic test
condition.
Indicator - When on, RESET indicates that the transport is in fault or diagnostic status. Two-digit display may contain a fault or diagnostic code.

Diagnostic Controls
The following describes diagnostic controls.
Switcb/
Indicator

Function

DIAGNOSTIC

Indicator - When on, DIAGNOSTIC indicates that the transport is in the
diagnostic/test mode. The indicator remains on until the RESET switch is
pressed.

TEST

Switch - If the transport has tape threaded but not loaded, pressing this
switch places the unit in the diagnostic/test mode.

STEP

Switch - If the transport is in the diagnostic/test mode (and the test number
is displayed), pressing this switch allows the diagnostic/test sequence numbers in the two-digit display to increment by one.

EXECUTE

Switch - If the transport is in the diagnostic/test mode (and the test number
is displayed), pressing this switch initiates the internal diagnostic test shown
on the two-digit display.

Switch - If the transport is in the diagnostic/test mode, this switch helps
run Field Service Diagnostics.

Operator's Hints
1.

When LOGIC ON indicator is on, all control panel switches and indicators are functional except
the LOGIC OFF indicator.

The ON-LINE switch can be pressed while tape is loading. The TU80 goes on-line immediately
when loaded.

When RESET indicator is on, the control panel is not operable except for the LOGIC OFF and
RESET switches. To turn the indicator off, press the RESET switch.

Tape unloading is performed at low speed. If there is a lot of tape on the take-up reel and you
wish to do it more quickly, you can do it faster by pressing LOAD REWIND first and then
UNLOAD.

OPERATING PROCEDURE
The operating procedure includes preparing and loading the tape reel, powering on the transport, placing it
on-line to the host computer and checking its operational status. If a fault code appears on the two-digit
display during loading or routine operation, refer to Operator Corrective Actions in this chapter.
Inserting Write-Enable Ring
Before mounting the reel of tape onto the supply hub, determine whether or not the tape is to be recorded
(write operation performed). If write operations are to be performed, place a write-enable ring into the
bottom recessed portion of the reel (Figure 2-2).
2-3

WRITE
ENABLE
RING

WRITE
ENABLE
RING
GROOVE
REEL

MA-0084-B2

Figure 2-2

Write-Enable Ring

When the reel is prepared, proceed as follows.
Tape Threading and Loading
Perform this procedure to thread and load tape.
NOTE
The circuit breaker on 874 Power Controller must be
ON.
1.

Pull the cover latch towards the front and lift the top access cover. Check that the power switch
is in ON position (1 pressed). The LOGIC OFF indicator should be on.
NOTE
The power switch can be in the ON position all the
time to enable the TU80 transport to be powered 'on
under CPU control.

Press the LOGIC ON switch. The power-up health check is initiated. The LOGIC OFF indicator goes off and all other indicators momentarily go on. The LOGIC ON and FILE PRO indicators should remain on.
NOTE
Pressing the LOGIC ON switch enables the transport power amplifier module, control logic, and support circuits. If a fault code displays at this time,
press the RESET and LOGIC OFF switches and
then the LOGIC ON switch again to repeat the
check.

Press the inner button on the face of the supply reel hub.

Mount the supply reel onto the hub so that the reel is seated on the bottom flange. Secure the
reel by pressing the periphery of the hub face to latch the reel.

Thread magnetic tape through the tape path as shown in Figure 2-3.

2-4

o
MA-0085-82

Figure 2-3

Tape Path

Wrap the tape leader (a length of tape before the BOT marker) onto the take-up reel for several
turns.
CAUTION
Make sure that the tape is positioned correctly over
all tape path components, otherwise, tape damage
may occur.

Close and latch the top cover.

Press the LOAD/REWIND switch. In one second air pressure builds at the air bearings and
tape starts moving in the forward direction. This motion stops when the BOT marker on the tape
is detected. If the tape was over-threaded and the BOT marker was positioned after the sensor,
forward tape motion continues for approximately 40 feet. Then the transport initiates reverse
tape motion until the BOT marker is detected. At this moment, tape motion stops and the BOT
indicator is on.
NOTE
If LOAD fails and tape does not move to BOT,
check for the BOT marker on the tape. If there is no
BOT marker, attach one by following the instructions in Chapter 4.

Press the ON-LINE switch to place the unit on-line to the host. The switch may be pressed while
the load operation is in progress. On completion of a load operation, the transport indicates ONLINE status by turning the ON-LINE indicator on. (If the transport is ready for a write operation, the FILE PRO indicator goes off.) Now the transport is ready for use.

2-5

Tape Unloading
The following are procedures for unloading tape manually or in on-line mode.

Manual Mode - Perform this procedure to unload tape manually.
1.

Press the RESET switch to place the transport off-line.

Press the UNLOAD switch. Tape moves in reverse direction (rewind) gently winding onto the
supply tape reel until it clears the take-up reel and the tape path.

NOTE
If loaded beyond the BOT marker, tape rewinds to
BOT.
3.

Open the top cover and press the center button of the supply reel hub. The hub unlatches and
the supply reel can be removed.

Close the top cover to prevent dust accumulation on the tape deck components.

On-Line Mode - When on-line to the host CPU, the UNLOAD operation can be performed under CPU
control. To remove the reel, perform steps 3 and 4 above.

OPERATOR CORRECTIVE ACTIONS
When you press the LOGIC ON switch, the TU80 transport initiates a built-in power-on health check. If a
failure is detected during this check, and a fault code is indicated on the display, the tape loading procedure
stops. Reset and repeat the check (refer to Power-On Health Check in Chapter 6) and then report any
displayed fault code to service personnel.

CAUTION
Do not try to locate and correct the malfunction
yourself.
During a load or read/write operation, if a fault occurs that cannot be corrected by the host computer and
the transport takes itself off-line, the operator is informed of the fault by the fault code in the two-digit
display. Refer to Table 2-1 for the list of fault codes and corresponding corrective actions.
The operator has an opportunity to check the TU80 transport operating condition using the built-in basic
Diagnostic Test a1 (refer to Chapter 3). This test can be used to check the basic operating functions of the
transport, or to verify a malfunction when a fault code indicates transport failure.
Refer to Chapter 3, Customer Diagnostics, for test information. Table 2-1 lists fault codes and operator
corrective actions.

2-6

Table 2-1

Operator Corrective Actions

Fault Code

Corrective Action

01-09

Clean the magnetic head and tape path following instructions in Chapter 4 of this manual.

Make sure the top cover is securely closed

Thread the tape.

Latch the supply reel hub.

Thread the tape correctly as shown on the tape threading diagram.

Check for BOT marker on tape. Attach BOT fEOT marker following instructions in
Chapter 4.

This fault code indicates that the RESET switch was pressed inadvertently. Reinitiate the
test.

Check for presence of the write-enable ring in the supply tape reel. Install the ring if not
present.

Check for presence of EOT marker. Attach EOT marker following instructions in
Chapter 4.

Indicates that the tape was loaded when the test was initiated. Thread the tape, but DO
NOT press LOAD switch.

20-29

Mount a tape of known good quality.

All others

Attempt to run Diagnostic Test 01 (refer to Chapter 3) and then report a fault code to Field
Service.

2-7

CHAPTER 3
CUSTOMER DIAGNOSTICS

INTRODUCTION
The built-in operator diagnostics allow the operator to functionally test transport performance, to run operator
diagnostics if there is a failure, or to check the transport condition after a long idle period.
OPERATOR TROUBLESHOOTING
If the transport fails, an operator can make a few minor checks to try to isolate an easily correctable malfunction before calling Field Service.
1.

Make sure that the tape has a BOT marker.

If a write operation is to be performed, make sure that the tape reel has the write-enable ring
installed.

Verify that the tape path is clean.

Verify that the power switch is ON (1).

In case of power failure, verify that the power controller circuit breaker is ON.

Make sure that the top cover door is closed and latched.

If data (Read/Write) errors are reported by the host computer, "first-aid" action is to clean the tape path
as described in Chapter 4, Care and Preventive Maintenance.
NOTE
During cleaning, take the time to inspect the tape
path components for defects; e.g., damaged tape
cleaner blades, loose air bearings, cracked or misaligned reel flanges causing contact with tape edges,
etc. Cleaning and inspecting components takes only
minutes, but goes a long way toward maintaining the
reliability of the transport and minimizing downtime.
If cleaning does not resolve the problem, then replace
the reel of tape with a tape of known good quality
used only for testing. If the fault persists after the
above procedures are performed, then the only
recourse is to report the fauIt to Field Service
Personnel.

3-1

Error Reporting
When the TU80 is on-line, the operator may become aware of an abnormal condition through a message on
the system's CRT monitor or the printer. The fault reports should be retained or logged by the host system
so that Field Service can determine not only the type of malfunction but all the circumstances under which
the fault occurred.
OPERATOR DIAGNOSTIC PROCEDURE
The operator diagnostics include the Power-On Health Check and one user-oriented, selectable test (0 I),
which runs for approximately ten minutes, if a 10.S-inch tape reel is used.
Optional tests 02 and 03 are also available to the operator. They should be run only if Field Service
Representative requests the operator to do so. Faults encountered during the tests stop the test and display
a numerical fault code on the digital display. Any fault code should be logged by the operator and given to
Field Service when the problem is reported.
Operator Diagnostic Tests
Power-On Health Check is automatically performed when the LOGIC ON switch is pressed. If this check
is successful, 00 is indicated on the two-digit display and the LOGIC ON and FILE PRO indicators go on
and stay on. The fault condition is indicated by a fault code on the display and the RESET indicator being
on. Refer to TU80 Acceptance Tests in Chapter 6 for more information on TU80 diagnostics.
Test 01 - This test examines the operating characteristics of the transport and points to the external (operator) or internal (hardware) causes of the failure.
The following are some external causes of failure that can be corrected by the operator.
•
•
•
•
•

Dirt in the tape path
Worn, damaged, or incorrectly written tape
Incorrectly threaded tape
No write-enable ring when one is required
Unlocked top cover

Internal causes are hardware (mechanical and electronics) problems which require intervention of Field
Service.
CAUTION
Test 01 reads and writes on tape; therefore, remove
any mounted tape to save the data on it. Replace it
with a tape of known good quality reserved for this
purpose.
To eliminate the possibility of false displays due to a display panel failure, the first portion of Operator
Diagnostic Test 01 is an exercise of the display panel indicators. The numerical display increments from 00
through 99. Concurrent with the numerical display, the following indicators are on: FILE PRO, LOGIC
ON, ON-LINE, RESET and DIAGNOSTICS.

3-2

Pre-test conditions are as follows.
1.

Make sure the power switch is in ON (1) position, LOGIC ON switch is pressed to run the
built-in Power-On Health Check (LOGIC ON indicator is on).

If a fault occurs at this time, do not attempt further testing; report error code to Field Service.
2.

Thread the tape through the tape path and onto the take-up reel, but DO NOT LOAD.

Close and latch the top cover.

Use the following procedure to perform Test 01.
1.

Press the RESET switch.

Press the TEST switch on the diagnostic portion of the control panel.

DIAGNOSTICS indicator goes on.

Display indicates 01.

Press the EXECUTE switch.
a.

Test 01 starts with display panel incrementing from 00, 11, 22 through 99. Make sure that
all segments of the numerical display are functioning.

Make sure that all indicators except LOGIC OFF, BOT and SELECT are on.

Test 01 continues with various tape motion and read/write exercises for approximately 10
minutes (with 2400 feet of tape).

If the test runs to completion, the transport performs a REWIND/UNLOAD operation and the digital
display indicates 00, with the RESET indicator on.
Perform the following if the test is not successful.
1.

The diagnostic program halts and a numerical fault code appears on the display, with the
RESET indicator on. Record this number.

Refer to Operator Corrective Actions (Table 2-1) for an operator action that may resolve faults
without Field Service involvement.

NOTE
Reinitiate Test 01 after performing any of the above
actions. If it is successful, return the TU80 to normal operation. If the fault is not resolved, proceed
with step 3.
3.

If the operator action did not correct the fault, report the number recorded in step 1 and any
different numbers to the Field Service.

In some cases, Field Service may ask the operator to run Diagnostic Tests 02 and 03. These are short tests
used to check tape tension and the velocity control servo system respectively.

3-3

Test 02 - Pre-test conditions are as follows.
1.

Make sure the transport is powered on.

Thread the tape but 00 NOT LOAD.

Close and latch the top cover.

Use the following procedure to perform Test 02.
1.

Press the RESET switch.

Press the TEST switch.

DIAGNOSTICS indicator goes on.

Display indicates 01.

Press the STEP switch one time. (Display number increments by 1 each time the STEP switch is
pressed.)
Numerical display steps from 01 to 02. If you make a mistake, press the RESET switch and
repeat steps 2 and 3.

Press the EXECUTE switch.
Test starts and runs for less than half a minute.
'\

If 00 displays, the run is successful. If the test is unsuccessful, the diagnostic program halts and a
certain numerical fault code appears on the display. The RESET indicator goes on. Record this number and report the fault to Field Service.

Test 03 - Pre-test conditions are as follows.
1.

Make sure the transport is powered on.

Make sure the tape is NOT threaded.

Close and latch the top cover.

Use the following procedure to perform Test 03.
1.

Press the RESET switch (this resets the fault code for Test 01, if still indicated).

Press the TEST switch.
a.

DIAGNOSTIC indicator goes on.

Display indicates 01.

3-4

Press the STEP switch twice (display number increments by 1 each time the STEP switch is
pressed).
Numerical display steps from 01 to 02 to 03. If you made a mistake, press the RESET switch
and repeat steps 2 and 3.

Press the EXECUTE switch.
Test starts and runs for less than one minute.

00 indicates a successful run. If the test is unsuccessful, the diagnostic program halts and a numerical
fault code appears on the display. The RESET indicator goes on. Record this number and report it
to Field Service.

3-5

CHAPTER 4
CARE AND PREVENTIVE MAINTENANCE

CUSTOMER RESPONSIBILITIES
The customer is responsible for the following:
1.

Obtaining operating supplies, including magnetic tape and cleaning supplies.

Keeping the exterior of the system and the surrounding area clean.

Make sure that ac power plugs are securely plugged in each time the equipment is used.

Performing the specific operations for equipment care described in this chapter at the suggested
periods, or more often if usage and environment warrant.

Also, it is recommended that the customer:
1.

Maintain the required logs and report files consistently and accurately.

Make the necessary documentation available in a location convenient to the system.

CARE OF MAGNETIC TAPE
Follow these precautions when using magnetic tape.
1.

Do not expose magnetic tape to excessive heat or dust. Most tape read errors are caused by dust
or dirt on the read/write head. It is important to keep tape clean.

Always store the tape reels inside containers when the tape is not in use. Keep empty containers
tightly closed to guard against dust and dirt.

Never touch the portion of tape between the Beginning-Of-Tape (BOT) and End-Of-Tape
(EOT) markers. Oil from fingers attracts dust and dirt.

Never use a contaminated reel of tape. This spreads dirt to the clean tape reels and could
adversely affect tape transport reliability.

Always handle tape reels by the hub hole. Squeezing the reel flanges leads to tape edge damage
when winding or unwinding tapes.

4-1

Do not smoke near the tape transport or storage area. Tobacco smoke and ash are especially
damaging to tapes.

Do not place magnetic tape near lineprinters or other devices that produce paper dust.

Do not place magnetic tape in any location where it may be affected by hot air.

Do not store magnetic tape near electric motors or any other magnetic sources that may erase
data.

Digital Equipment Corporation tape transports are highly reliable precision instruments that provide years
of trouble-free performance when properly maintained. A program of routine inspection and maintenance
is essential for optimum performance and reliability. The following information will assist the user in caring
for equipment.
.
TAPE TRANSPORT CUSTOMER MAINTENANCE
To guarantee trouble-free operation, the user, should keep a preventive maintenance schedule. Preventive
maintenance consists of cleaning only a few items, but the cleanliness of these items is essential to proper
tape transport operation. The frequency of maintenance operations varies with the environment and the
amount of usage the transport receives. Therefore, a rigid schedule for all machines is difficult to define.
Daily cleaning is recommended for units in constant operation in ordinary environments. This schedule
should be modified if experience shows other periods are more suitable.
Before any cleaning, remove the supply reel and store it properly. When cleaning, be gentle but thorough.
CAUTION
Do not use acetone, lacquer thinner, rubbing alcohol,
or trichlorethylene to clean the tape path.
Magnetic Tape Transport Cleaning Kit
A magnetic tape transport cleaning kit (TUCDl) has been carefully assembled to provide cleaning materials that will not harm tape equipment or leave residue to interfere with data reliability. Follow the hints in
the following paragraphs to get the best results from the kit.
The cleaning fluid in this kit is one of the best cleaners available. Unscrew the top and punch a small hole in
the metal seal covering the pour spout.
WARNING
When using DEC magtape cleaning fluid, avoid
excessive skin contact and contact with the eyes. Do
not swallow it. Use the cleaning fluid only in a wellventilated area.
CAUTION
When cleaning the tape equipment, never dip a dirty
cleaning swab or wipe into the can. Instead pour a
little onto the swab or wipe. Use the smallest amount
of cleaning fluid necessary. DO NOT soak the swab
or wipe in the cleaning fluid.
Always keep the can of fluid tightly closed when not in use; the fluid evaporates rapidly when exposed to
air.

4-2

Use the cleaning materials from the kit to clean tape heads, tape guides, tape cleaner, and any part of the
drive, where residue could contact the tape. To clean other parts of the drive, such as the exterior tape deck
-surfaces, doors, etc., use any reasonably clean, lint-free material with or without cleaning fluid.
CAUTION
To clean exterior surfaces, only use soap and water.

If you encounter any unusually stubborn dirt that resists the cleaner, try a mild soap and water solution.
After using soap, be sure to wash down the area thoroughly with cleaning fluid to remove soapy residue.
Reflective Tape Markers
Every reel of magnetic tape must have a BOT and an EOT reflective marker, so that the transport can
recognize starting and stopping areas. Tapes are always supplied with reflective markers installed.
However, if the markers become detached for any reason or, if a tape leader is shortened because of tape
damage, then the operator must install a marker at the position shown in Figure 4-1.

TAPE

EDGE CLOSEST

SHINY
BACK SIDE

4.87±.60M

MAGNETIC~

BACK
SIDE
HUB

~END

SIDE
RIM

END,

FRONT VIEW
OF TAPE WIND

RIM END
(BEGINNING)

MA-0086-B2

Figure 4-1

Reflective Tape Markers

4-3

Transport Oeaning
All transport components that need regular cleaning are located on the tape deck. These components
include the magnetic head assembly, EOT/BOT sensor, tape cleaner, and air bearings. Also, the user
should regularly examine and clean, as required, the top of the tape deck, reel hubs, and top cover door.
To access the magnetic head components (Figure 4-2), pull up the two-part head assembly dust cover from
the tape deck.
Magnetic Heads - Use the following procedure to clean magnetic heads.
1.

Clean the magnetic head working surface with a soft lint-free wipe moistened with the cleaning
fluid.

NOTE
Wipe the head surface in the same direction that the
tape travels during data recording (forward motion).
2.

Clean area adjacent to the head of any dirt that can be transported with the tape.

DUST COVERS

MAGNETIC HEAD

UPPER AIR
BEARING

TAPE CLEANER

LOWER AIR
BEARING

EOT/BOT SENSOR
MA-0087·82

Figure 4-2

Magnetic Head/Tape Path Components

4-4

Air Bearings - Use the following procedure to clean the air bearings.
1.

Clean both air bearings with a swab moistened with the cleaning fluid.

Make sure that foil area, guide springs, and both tape guides are cleared of any oxide/dirt buildup. If available, use a small mirror to inspect inner edge of the guides.

Top Cover, Tape Deck, and Head Assembly Dust Covers - To prevent the transfer of dirt to the tape
components, 00 NOT allow dust or dirt to accumulate on the inside of the dust cover. Clean the inside
cover surface with a clean, lint-free wipe and any cleaning fluid that is safe for plastic, painted surfaces.
ACCESSORIES AND SUPPLIES
To use the TU80 Subsystem efficiently, the following accessories and supplies should be available for the
operator.
1.

2.
3.

Magnetic Tape Cleaning Kit (TUCO 1)
Magnetic Tapes
BOT/EaT Marker Tape (PN 90-09177-00)

Ordering
Purchase orders for supplies, accessories or documentation should be forwarded to:
Digital Equipment Corporation
Accessories and Supplies Group
PO Box CS2008
Nashua, New Hampshire 03061.
Contact your local sales office or call DIGITAL Direct Catalog Sales toll-free 800-258-1710 from 8:30 am
to 6:00 pm eastern time (US customers only). Customers from New Hampshire, Alaska, and Hawaii
should dial (603)884-6660. Terms and conditions include net 30 days and FOB DIGITAL plant. Freight
charges will be prepaid by DIGITAL and added to the invoice. Minimum order is $35.00. Minimum does
not apply when full payment is submitted with an order. Checks and money orders should be made out to
Digital Equipment Corporation.

4-5

CHAPTERS
PROGRAMMING

INTRODUCTION
This chapter provides operational information and a functional description of the TUSO registers and packet processing. It also gives programming techniques and performance-improving hints (with programming
examples and packet formats) to show basic TUSO programming concepts and advanced performance.
TU80 PERFORMANCE EVALUATION
Speed Modes and Speed Selection
The TUSO operates at one of three speeds selected by the TUSO to optimize data throughput.
•
•
•

25 in/s start/stop
25 in/s streaming
100 in/s streaming

In the 25 in/s start/stop speed, the TUSO is capable of stopping and starting within an ANSI minimum
interblock gap of 0.6 inches when reading. However, if the TUSO stops after a write in this speed mode, the
gap written is O.S inches. A stop or a start in this mode takes 20 milliseconds (nominal), and is similar to the
stopping and starting of a "conventional" (nonstreaming) tape transport.
In the 25 in/s or 100 in/s streaming speeds, the TUSO always writes ANSI minimum gaps of 0.6 inches
but is operating as a "streaming tape" transport. When streaming, the TUSO is not capable of starting and
stopping in the interblock gap (lBG), as are conventional tape drives. When a streaming drive does have to
stop, it:
•
•
•
•

Slowly coasts forward to a stop.
Backs up over a section of tape previously processed.
Awaits the next command.
Accelerates, taking a running start so that when it encounters the original IBG, it is at full speed.

This cycle is called repositioning. Approximately 0.2 seconds at 25 in/s and 0.7 seconds at 100 in/s are
required to complete an entire repositioning cycle. If the CPU is not capable of supplying data to, or
accepting data from, a streaming tape drive at a rate that keeps the drive constantly in motion (streaming),
the drive repositions when it has run out of commands to execute. In this instance, thrashing can occur.
(Thrashing is when extremely long reposition times overwhelm the time spent processing data. This results
in poor data throughput.

5-1

The TU80 has a microprocessor-based adaptive speed control system which is designed to eliminate the
thrashing phenomenon. The adaptive speed control feature automatically changes the TU80 speed from
100 in/s streaming to 25 in/s streaming if excessive repositioning is sensed. Conversely, if the TU80 has
been successfully streaming at 25 in/s for a determined time period, the adaptive speed control changes the
speed to 100 in/so A similar algorithm controls speed changing from 25 in/s start/stop to 25 in/s streaming, and vice versa.
If the adaptive speed control system changes TU80 speed from 25 in/s to 100 in/s, and vice versa, too
often within a determined time, the TU80 stops trying to operate at 100 in/so The TU80 tries 100 in/s
again after the algorithm is reset by the occurrence of the rewind and initialize commands, or after encountering a tape mark (read or write).

The TU80 adaptive speed control feature is not user-programmable. It can be thought of as an automatic
transmission on a vehicle which matches engine RPMs (i.e., CPU data rate to the tape) to vehicle speed
(i.e., speed mode of TU80) to attain best performance.

TUBa PERFORMANCE WITHOUT
DATA BUFFERING
ACHIEVED
AVERAGE
TAPE SPEED 100
(IPS)

/
BETTER

l00IPS
STREAMING

AREA OF
INEFFICIENCY

~
_,.....~~......................~I- SPEED SWITCH

25IPS

25 IPS

STREAMING,,;4- l00JPS THRASHING-PREVENTED BY
~~R2, ~O!.. _ , /
ADAPTIVE SPEED CONTROL
100

POTENTIAL TAPE SPEED
(IPS)

ACHIEVED
AVERAGE
100
TAPE
SPEED
(IPS)

TUBa PERFORMANCE WITH
DATA BUFFERING

/
/

BETTER

l00IPS
STREAMING

AREA OF
INEFFICIENCY

100
MA-0088-82

Figure 5-1

Data Buffering and TU80 Performance Upgrading

5-2

Performance Hints
The frequency of TU80 repositioning is entirely application-dependent - a function of how fast the CPU
can process data, relative to the tape speed of the transport while it's streaming. One way to increase the
probability of 100 in/s streaming is to build a large data buffer in main memory that can deliver or accept
data at tape-streaming rates. This makes sure that a known, large amount of data is processed (the data in
the buffer) prior to a potential reposition cycle. The total percentage of time the tape drive is doing useful
work is then increased, relative to the time spent repositioning, and the adaptive speed control system is
more likely to maintain a higher perform.ance speed selection.
A buffer allocated by the application's program should have the capacity of at least 32K bytes (e.g., eight
4K byte records) to help attain better overall performance. Furthermore, a ring buffer type is suggested,
i.e., reading and writing into the buffer should occur at the same time in an attempt to prevent or delay an
empty buffer condition.
Of course, if the potential data rate to or from the host CPU is greater than the tape streaming rate, then
the tape streams and no buffering is necessary. However, if the potential rate drops below the streaming
rate, the buffer reduces the frequency of repositioning and there are enhanced opportunities for high-speed
streaming. Figure 5-1 shows how data buffering enhances performance.
In several cases DIGITAL operating systems have the capability of buffering I/O channels. An example is
the Multi-Buffered File Control System of RSX-IIM. Wherever possible, operating system features of this
type should be selected to also enhance opportunities for high-speed streaming.
TU80 REGISTERS
When using the TU80 tape transport, it is important to understand that command and data packets are
used to transfer command and data information to the transport. The traditional method of writing a command or data word to a UNIBUS register is not used. A command packet consists of a command word and
up to three additional words of command modifiers or qualifiers. This command packet is assembled in
host CPU memory space on modulo-4 memory addresses. The beginning address of the command packet is
the command pointer. Only the high 16-bits of an I8-bit word are used. This pointer is used by the controller to NPR transfer the command packet to the subsystem.
The following are the eight TU80 (M7454) registers.
TSBA
TSOB
TSSR
XST

(1) - UNIBUS Address Register
(1) - UNIBUS Oata Buffer
(1) - Status Register
(5) - Extended Status Registers

TSBA (UNIBUS Address Register - Base Address - Read Only)
The TSBA is an I8-bit register. It is parallel loaded from the TSOB every time the TSOB is loaded as a
UNIBUS slave· by the CPU. TSOB bits 15-2 load into TSBA bits 15-2; and TSOB bits 1 and 0 load into
TSBA bits 17 and 16. Zeros are loaded into TSBA bits 1 and O. TSBA bits 17 and 16 are displayed in
TSSR bits 9 and 8 respectively. TSBA can be instructed by the transport to increment or decrement by two
for non processor request (NPR) word transfers, or by one for NPR byte transfers. The TSBA is the base
address in the read only mode and it is not cleared on power up, subsystem INIT, or bus INIT. It can also
be read at any time with or without the drive unit connected.

5-3

Figure 5-2 shows the TSBA register. Table 5-1 lists and defines the bits. The TSBA register serves the
following two major purposes.
1.

The TSBA can be used as a command and message pointer to the remote transport device registers (command and message buffers). These are located somewhere in the UNIBUS address
space. The content, loaded into TSDB when the M7454 is the bus slave, is considered the command or message pointer. In this mode, the M7454 receives data (initiated by the transport) at
this command pointer address and sends it to the transport for storage and/or execution. The
message buffer address tells the M7454 where to place the message sent to the CPU address
space. When used as a message pointer, the highest message buffer address + 2 is left in the
TSBA.

The TSBA ,can be used as a data pointer (NPR's bus address 0), pointing to data buffer areas
located somewhere in the UNIBUS address space. [In this mode, the transport serially loads the
TSDB with data (18 address bits); TSDB bits 17 through 0 load into TSBA bits 17 through 0,
but bits 17 and 16 are displayed in TSSR bits 9 and 8, respectively.] The contents of TSBA are
then used to point to data buffer areas while the M7454 transfers data by NPRs.

MA-2944

Figure 5-2

TSBA Register

Table 5-1

TSBA Bit Definitions

Bit

Name

Definition

A17
A16
A15
A14
A13
A12
All
AI0
A09
A08
A07
A06
A05
A04
A03
A02
A01
AOO

Bus address bit 17
Bus address bit 16
Bus address bit 15
Bus address bit 14
Bus address bit 13
Bus address bit 12
Bus address bit 11
Bus address bit 10
Bus address bit 09
Bus address bit 08
Bus address bit 07
Bus address bit 06
Bus address bit 05
Bus address bit 04
Bus address bit 03
Bus address bit 02
Bus address bit 01
Bus address bit 00

16
15
14
13
12

11
10
09
08
07
06
05
04

03
02
01
00

5-4

TSDB (UNIBUS Data Buffer Register - Base Address - Write Only)
The TSDB is an 18-bit register. It is parallel loaded from the UNIBUS or serially loaded from the transport. A 16-bit portion of this register is used as a word buffer register to the M7454 when the M7454 is the
bus slave (for beginning an operation). The same word buffer register is also used by the transport (for data
during NPR transfers) when the M7454 is bus master. The TSBD can be loaded when the M7454 is bus
slave by three different transfers from a bus master. Two transfers are for maintenance purposes (DATOB
to high byte and DATOB to low byte). The third transfer is for normal (word) operation (DATO). This
register is write only and is not cleared at power up, subsystem initialize, or bus initialize. It cannot be
loaded without the complete transport unit connected and a serial bus synchronous clock. The M7454
responds with SSYN any time the TSDB is written to.
Figure 5-3 shows the TSDB register. Table 5-2 lists and define the bits.
Normal Operation - When TSDB is loaded by a DATO (write a word to TSDB) the following happens. Bit

o and bit 1 are loaded with zeros. Bits 2 through 15 are loaded with bits 2 through 15, respectively, from

the UNIBUS. Bits 16 and 17 are loaded from bits 0 and 1, respectively, from the UNIBUS. The bus
address is 17XXXX, where XXXX can be any unused address from 0 through 17776. The M7454 indicates to the transport a TSDB word load when the M7454 is bus slave.

MA-2945

Figure 5-3

TSDB Register (Loaded with a Command Pointer)

Table 5-2 TSDB Bit Definitions
Bit

Name

Definition

15
14
13
12
11
10
09
08
07
06
05
04
03
02
01
00

PI5
P14
P13
PI2
PI 1

Command pointer bit 15
Command pointer bit 14
Command pointer bit 13
Command pointer bit 12
Command pointer bit 11
Command pointer bit 10
Command pointer bit 09
Command pointer bit 08
Command pointer bit 07
Command pointer bit 06
Command pointer bit 05
Command pointer bit 04
Command pointer bit 03
Command pointer bit 02
Command pointer bit 01
Command pointer bit 00

PIO
P09
P08
P07
P06
P05
P04
P03
P02

POI
POO

5-5

TSSR (Status Register - Base Address + 2 - Read/Write)
The TSSR is a 16-bit register that can only be updated from the transport or internal M7454 logic. The
TSSR cannot be modified from the UNIBUS except for RMR, NXM, and SSR bits that are cleared when
the TSDB is written by the host CPU. It is a read/write register at base address 17XXXX+2. (The
DATO/DATOB write transfers cause the M7454 to modify 17XXXX+2.) It can be read at any time with
or without the transport unit connected. Figure 5-4 shows the bit positions and Table 5-3 describes the bits.
TSSR register bits 14 through 11 and 7 are cleared only on system power up, TU80 power up, subsystem
initialize, or at the beginning of any write command to the TSSR register. Bits 15 and 7 are also under
control of the transport. These may be set or cleared independently of any TU80 operation. Bits 10 and 6-0
are exclusively controlled by the transport and reflect the transport status as indicated.

NOTE
Any write function to the M7454 base address
1725XX is decoded as a subsystem initialize. This
resets the M7454 and TU80 no matter what state
they are in and causes an automatic load sequence
returning the tape to BOT if the TU80 is on-line.
The TSSR register uses several bits to increase its status reporting capabilities. TSSR bits 4 and 5 report
four fatal class error codes and TSSR bits 1, 2, and 3 report seven termination class status codes. Fatal
error bits are valid only if the termination class equals 7.
On fatal errors (fatal class bits equal seven), if the need buffer address is not set (NBA=O), then the message may be valid. If the need buffer address is set (NBA=I), then there was no message.
The RMR bit does not affect the error class codes because RMR may occur on a bug-free system.
However, RMR sets the special condition (SC). (You may have tried to perform the next command while
the drive was outputting the ATIN MSG.) If RMR is seen in the TSSR, the CPU must have written the
TSDB while the command was executing.

MA-2953A

Figure 5-4

TSSR Register

5-6

Table 5-3 TSSR Bit Definitions

Bit

Name

Causes
Termination
Class (TC)

Definition
Special Condition - When set, this bit indicates that an incident occurred
before the last command completed. Specifically, either an error was detected
or an exception condition occurred. An exception condition could be a tape
mark on read commands, reverse motion at BOT, EaT while writing, etc.

Not used

RMR

Register Modification Refused - This bit is set by the M7454 when a command
pointer is loaded into TSDB and subsystem ready (SSR) is not set. This bit may
set on a bug-free system if A TIN interrupts are enabled.

NXM

4/5

Nonexistent Memory - This bit is set by the M7454 when trying to transfer to
or from a memory location that does not exist. It may occur when fetching the
command packet, fetching or storing data, or storing the message packet.

NBA

Need Buffer Address - When set, this indicates that the transport needs a message buffer address. This bit is cleared during the set characteristics command
if the transport gets valid data. This bit is always set after subsystem
initialization.

A17

Bus Address Bit 17 - AI7 and AI6 (bits 08 and 09) display the values of bits
17 and 16 in the TSBA register.

A16

Bus Address Bit 16 - Refer to A 17 above (bit 09).

SSR

Subsystem Ready - When set, this bit indicates that the TU80 Subsystem is
not busy and is ready to accept a new command pointer.

OFL

Off-Line - When set, this bit indicates that the transport is off-line and unavailable for any tape motion commands.

Not used

TC2

Termination Class Bit 02 - This bit, along with the TCI and TCO bits, acts as
an offset value when an error or exception condition occurs on a command.
Each of the eight possible values of this field represents a particular class of
errors or exceptions. The conditions in each class have similar significance and,
as applicable, recovery procedures. The code provided in this field is expected
to be used as an offset into a dispatch table for handling the condition. These
bits are valid only when special condition (SC) is set. Refer to Special
Conditions and Errors.

TCI

Termination Class Bit 01 - Refer to TC2 (bit 03) above.

TCO

Termination Class Bit 00 - Refer to TC2 (bit 03) above.

Not used

5-7

XST (Extended Status Registers)
Five additional registers provide additional status information: residual frame count register (RBPCR) and
extended status register 0, 1, 2, and 3. Figure 5-5 shows these registers. Tables 5-4 through 5-8 define the
bits.
TU80 Register Summary
Figure 5-5 is a summary of the TU80 registers.

Bits
15

A14

A13

A12

All

Al0

A09

07
A07

A06

05
A05

A04

03
A03

02
A02

A15

08
A08

T SBA
( R/O)

AOl

AOO

T SOB
(W/O)

P15

P14

P13

P12

Pll

Pl0

P09

P08

P07

P06

P05

P04

P03

P02

P17

P16

RMR

NXM

NBA

A17

A16

SSP

OFL

TC2

TCl

TCO

4/5

C06

C05

C04

C03

CO2

Cal

COO

REGISTE R

T SSR

RBPCR

C15

C14

C13

C12

Cll

C10

COO

C08

C07

TMK

RLS

LET

RLL

WLE

NEF

ILC

ILA

MOT

ONL

VCK

PED

WLK

BOT

EOT

S/2
DLT

2
COR

3/6

S/1/3

S/3

S/3/6

S/2/3
UNC

MTE

XSTO
IPO

RPE

S/2

XSTl
S

4
OPM

TU80

4
DTP

DT7

DT6

S/4
DT5

S
OPI

S
REV

DT4

DT2

4
DTl

4
DTO

S
DCK

S
RIB

XST2
S
TRANSPORT ERROR CODE

XST3
7

1717[7171

S/6

Termination Class Codes:

o
3
4
5
6

Normal Termination
Attention Condition
Tape Status Alert
FL.nction Reject
Recoverable Error· Tape Position = One record
down tape from start of function
Recoverable Error· Tape not removed
Unrecoverable Error· Tape position lost
Fatal Controller Error

Fatal Class (FC) Codes (in TSSR): (NOT USED)
NON·TERMINATION CLASS CODE: S= STATUS
MA·2845C

Figure 5-5

TU80 Register Summary

5-8

Table 5-4 RBPCR Bit Descriptions
Bit

Name

Description

15-0

CIS-CO

This word contains the octal count of residual bytes, records, tape marks for the read, space
records, and skip tape mark commands. The contents are meaningless for all other
commands.

Table 5-5 XSTATO Bit Definitions

Bit

Name

Causes
Termination
Class (TC)

TMK

Sj2

Tape Mark Detected - This bit is set when a tape mark is detected during a
read, space, or skip command and as a result of the write tape mark or write
tape mark retry commands.

RLS

Record Length Short - Thi~ bit indicates one of the following three cases.

LET

Definition

The record length was shorter than the byte count on read operations.

A space record operation encountered a tape mark or BOT before the
position count was exhausted.

A skip tape marks command was terminated by encountering BOT or a
double tape mark (if skip tape marks command is enabled, see LET)
before exhausting the position counter.

Logical End of Tape - This is set only on the skip tape marks command under
two conditions:
1.

When either two contiguous tape marks are detected.

When moving off BOT and the first record encountered is a tape mark.

The setting of this bit will not occur unless this mode of termination is enabled
through use of the set characteristics command.

RLL

Record Length Long - When set, this bit indicates that the record read was
longer than the byte count specified.

WLE

3,6

Write Lock Error - When set, a TC3 indicates that a write operation was issued
but the mounted tape did not contain a write-enable ring. When set, TC6 indicates the WR T LOCK switch was activated during write operation.

5-9

Table 5-5 XST ATO Bit Definitions (Cont)

Bit

Name

Causes
Termination
Class (TC)

NEF

Definition
Non-Executable Function - When set, this bit indicates that the command
could not be executed due to one of the following conditions.
1.

The command specified reverse tape direction but the tape was already
positioned at BOT.

A motion command was issued without the clear volume check (CVC) bit
being set while the volume check bit was set.

A write command was issued when the tape did not contain a writeenable ring [write lock status (WLS)].

ILC

Illegal Command - This bit is set when a command is issued and either its command field or its command mode field contains codes not supported by the
transport.

ILA

Illegal address

MOT

This bit indicates that tape was moved during an operation.

ONL

S/1/3

On-Line - When set, this bit indicates that the transport is on-line and operable.
It causes a TC1 on A TIN interrupt or a TC3 for a nonexecutable function if
rejected because the transport was off-line.

Interrupt Enable - This bit reflects the state of the interrupt enable bit supplied
on the last command.

VCK

S/3

Volume Check - This bit is set when the transport changes state (on-line to
off-line and vice versa). It is always set after initialization.

PED

Phase Encoded Drive - When set, this bit indicates that the transport is capable
of reading and writing only 1600 bit/in phase encoded data. It should always be
set.

WLK

S/3/6

Write Locked - When set, this bit indicates that the mounted tape reel does not
have a write-enable ring installed. Therefore, the tape is write protected.

BOT

S/2/3

Beginning of Tape - When set, this bit indicates that the tape is positioned at
the load point as denoted by the BOT reflective strip on the tape. This causes
TC2 if reversed in BOT, and TC3 if at BOT when a reverse command occurs.

EOT

S/2

End of Tape - This bit is set whenever the tape is positioned at or beyond the
end-of-tape reflective strip. It is not reset until the tape passes over the reflective strip in the reverse direction under program control. Subsystem initialization always resets this bit (status on read, TC2 on a write). Manually moving
EaT mark over the EaT sensor will not set or reset the EaT bit.

5-10

Table 5-6 XSTATl Bit Definitions

Bit

Name

Causes
Termination
Class (TC)

DLT

14
13

Definition
Data Late - This bit is set when the I/O silo is full on a read or empty on a
write. The conditions occur whenever the UNIBUS latency exceeds the transport's data transfer rate for a significant number of transfers.
Not used

COR

Correctable Data - This bit is set when a correctable data error has been
encountered (on a read command only). It does not cause a termination class
error but there is a dead track. Dead track bits indicate the error. This is used
primarily as a diagnostic feature.

Not used

Read Bus Parity Error - Indicates a data parity error was detected by the coupler
on data received from the tape transport.

Not used

IPO

S/4

Invalid Postamble - This bit is set during read or write if any of the first 39
characters of the postamble are not read correctly. It is status on read, TC4 on
a write.

Not used

UNC

Uncorrectable Data - This bit is set when a parity error occurs without a corresponding dead track indication. This bit is a normal write error for any dead
track.

MTE

Multitrack Error - This bit is set if more than one dead track occurs in the
preamble or in the data field.

5-11

Table 5-7 XSTAT2 Bit Definitions

Bit

Name

Causes
Termination
Class (TC)

OPM

Definition
Operation In Progress (Tape moved)

Not used

CAF

TU80

Not used
TU80 Identifier - This is always set.

Not used

DTP

Dead Track Parity - This bit indicates which tracks went dead, if any, during
the last data transfer operation. If deskew buffer fail (DBF) is set, these bits
indicate which channel failed.

DT7

Dead track 7 *

DT6

Dead track 6 *

DT5

Dead track 5*

DT4

Dead track 4 *

DT3

Dead track 3 *

DT2

Dead track 2 *

DTI

Dead track 1*

DTO

Dead track 0*
NOTE
On the write characteristic command, bits 07 through 00
contain the microcode revision level of the M7454.

*Refer to Bit 08, DTP.

5-12

Table 5-8 XST AT3 Bit Definitions

Bit

Name

15-08 TEe

Causes
Termination
Class (TC)

Definition

Transport Error Code - These bits contain the error code shown on the front
control panel display of the transport.
Not used

07
06

OPI

Operation Incomplete - This bit is set when a read, space, or skip operation has
moved 25 feet of tape without detecting any data on the tape. It is also set by a
write command when the read head fails to see data transitions after four feet of
tape.

REV

Reverse - This bit is set when the direction of current tape operation is reversed.
For multifunction retry commands, if at least one of the commands is reversed,
the bit is set.
Not used

04
03

OCK

S/6

Density Check - The current operation will be done. However, note that read,
space, and skip operations complete without error (if no other errors occur) to
allow tapes with a bad IDB to be read. On a write command, when a bad IDB is
sensed, tape position lost occurs.

NOTE
If you append to a tape with a bad IDB, you will receive
any DCK error until a write.
02

Not used

RIB

Reverse Into BOT - This bit is set when a read, space, skip, or reverse command
already in progress encounters the BOT marker when moving tape in the reverse
direction. Tape motion is halted at BOT.

PACKET PROCESSING
The packet protocol scheme allows the drive to send a large amount of status and error information to the
CPU while using up only two words of UNIBUS address space. The packet protocol also prevents the drive
from updating the error and status information asynchronously, that is, while the CPU is reading the error
and status information.
NOTE
This section is not intended to detail all aspects of
packet protocol or packet processing. It is intended
to show how these concepts are implemented in the
TU80 Subsystem.

5-13

To allow the drive to use only two words of address space, we allow the CPU to define a set of locations in
memory. These locations (command buffers) are used to tell the drive which operation to perform. The
CPU also defines a set of locations (message buffers) in memory where the drive puts the error and status
information. The CPU must give both the command buffer address and message buffer address to the
drive. The CPU gives the command buffer address to the drive on every command. (The CPU writes the
address of the command packet into the TSDB of the drive.) The CPU gives the message buffer address to
the drive every time the CPU does a set characteristics command.
To prevent the drive from updating the message buffer while the CPU is reading the message buffer, we
have defined the concept of ownership. Both the command and message buffers can be owned. Each buffer
may be owned by the drive or the CPU, but not by both at the same time. Ownership of a buffer can only
be transferred by the current owner.
There are four different combinations that transfer the ownership of the two buffers.
1.
2.
3.
4.

Command buffer CPU to drive by the CPU
Command buffer drive to CPU by the drive
Message buffer CPU to drive by the CPU
Message buffer drive to the CPU by the drive.

The CPU transfers ownership of the command buffer to the drive by writing the address of the command
packet into the TSDB. This write clears the TSSR subsystem ready (SSR) bit.
The drive transfers ownership of the command buffer to the CPU by setting the acknowledge (ACK) bit in
the message buffer. When the drive outputs the message buffer, the drive sets SSR in the TSSR to indicate
that the message is in the message buffer. If the message buffer does not contain the ACK bit, the CPU
knows that the drive did not see the last command buffer and the CPU still owns the command buffer. The
command may be reissued by the CPU.
The CPU transfers ownership of the message buffer to the drive by setting the ACK bit in the command
buffer. If the command buffer does not contain the ACK bit, the drive knows that the CPU did not see the
last message buffer and the drive still owns the message buffer. The drive outputs the TSSR again (with the
SSR bit up) and interrupts (if IE is set) without sending a message.
The drive transfers ownership of the message buffer to the CPU in one of two ways. The first way is used
after the end of a command: the drive sets the SSR bit in the TSSR to indicate that the command is done
(and interrupts if IE is set). The second way is used during an attention (ATTN). SSR is already up because
an ATTN only happens when the drive is inactive. The drive clears SSR, outputs the message, then sets
SSR again and interrupts (if IE set). Note that if the CPU writes the TSDB while the SSR is clear during
an ATTN, the register modification refused (RMR) error bit is set and that command is ignored. The
ATTN message will not have the ACK bit set since the drive does not own the command buffer. Note that
RMR may set in this way on a bug-free system because the CPU tried to perform a command at the same
time the drive wanted to perform an ATTN. All other settings of the RMR indicate a software bug. (The
CPU tried to do a command before the previous command was finished.) If the CPU command was lost
because the transport was outputting an ATTN message, VOL CHK and INT ENB are not updated. If the
CPU command was rejected (illegal command, etc.), VOL CHK and INT ENB are updated to the start of
the rejected command.

5-14

When the drive is initialized, the drive updates the TSSR. At this time we define both the command and
message buffers as belonging to the CPU. When the CPU wants to do a command (the first one must be a
set characteristics to set up the message buffer address), the CPU writes the address of the command
buffer into the TSDB of the drive. This command must have the ACK bit set to give ownership of the
message buffer to the drive. At this point, the drive owns both the command and message buffers.
The drive executes the set characteristics command and sends out a message to the message buffer address
with the ACK bit set. This indicates that the drive recognized the command and is finished with the command buffer. The drive then sets SSR and interrupt (if IE is set). At this point, the CPU owns both the
message and command buffers again.
As you can see, the ownership of both buffers transfers from CPU to drive and then from drive to CPU at
the same time. Now consider the case where A TINs are enabled by the proper characteristics mode word
and the drive wants to do an ATIN. An ATTN only occurs when the drive is not active. If the CPU owns
both the command and message buffers, the drive must queue up the ATIN and not do anything until the
CPU releases the message buffer on the next command. So when the CPU executes the next command
(with the ACK bit set), the drive outputs the ATIN message with the ACK bit O. This indicates that the
command was lost (except for the transfer of the message buffer ownership to the drive). The drive refuses
to accept ownership of the command buffer. The CPU then still owns the command buffer (because the
drive did not accept the command) and also owns the message buffer now filled with an ATTN message. If
the CPU still wants to do the ignored command, the CPU must reissue the command (with the ACK bit
set).
Now consider the case where the CPU wants to be notified of a change in status right away while the drive
is inactive for a long period of time. To do this, the drive must own the message buffer for that long period
of time. Everything until now has indicated that the drive gives up the message buffer at the end of every
command. The message buffer release command is a special command from the CPU. It tells the drive not
to give ownership of the message buffer back to the CPU at the end of the command. The drive does not
output a message at the end of the command but just outputs the TSSR (with the SSR bit set) and interrupts (if the proper characteristics mode word is set up). The drive then maintains ownership of the message buffer until an ATTN condition is seen. The drive then immediately clears SSR, outputs the message
(with the ACK bit not set since the drive is not responding to a command), and then sets SSR and interrupts (if IE is set). At that time the system is back to the state of the CPU owning both buffers. Another
ATIN is not done until the CPU does a command with the ACK bit set to release ownership of the message buffer containing the ATTN message.
Suppose the CPU has done a message buffer release command and wants to do another command but has
not received an ATTN from the drive (so that the drive still owns the message buffer from the message
buffer release command). The CPU can do a command without the ACK bit set in the command buffer.
At the time of the command, the CPU does not own the message buffer so the CPU cannot release the
message buffer. If the CPU does set the ACK bit, nothing happens (except the CPU might miss an ATTN
if the drive was sending out an ATIN at the same time that the CPU was doing a command).
Message packet protocol may be violated if the transport gets an error (e.g., NXM) during the reading inof
the message packet. When one of these errors occurs, the transport always sends out a failure message
(because the packet is not reliable).
The system software should be written so it will not crash if the TU80 M7454 interrupts while the CPU is
servicing a TU80 M7454 interrupt. However, this case may happen, but only if the TU80 receives a fatal
hard ware error.

5-15

Command Packet/Header Word
Figure 5-6 shows the command packet/header word Table 5-9 defines it. Table 5-10 gives the command
code and mode field definitions.
Bits 3 and 4 of the command code field determine the format and length of command packets. The command packet formats and lengths are as follows.
Code
Bits

Definition

OOXXX
01XXX

Four words (header, two word address, count)
Two words (header, parameter word) or one word
(header)

CTL

DEVICE
DEPENDENT

ACK

C
V
C

0
P
P

COMMAND
MODE

S
W
B

4
COMMAND
CODE

PACKET
FORMAT 1
M

MA·2957

Figure 5-6

Command Packet Header Word

Table 5-9 Command Packet Header Word Bit Definitions
Bit

Name

Function

Acknowledge

This bit is set when a command is issued and the CPU owns the message buffer. It
informs the M7454 that the message buffer is now available for any pending or subsequent message packets. This passes ownership of the message buffer to the transport.

14-12

Device Dependent
Bits/Field

The following shows how these three bits are implemented.
Bit

Name

Definition

14
13

CVC
OPP

SWB

Clear volume check
Opposite (reverse the execution
sequence of the reread commands)
Swap bytes

11-8

Command Mode
Field

This bit acts as an extension to the code and mode field and allows specification of
extended device commands (seek, rewind, erase, write tape mark, etc.). Command
code and mode field are detailed in Table 5-10.

7-5

Packet Format
Field

The following two values are defmed in this field.

4-0

Command Code

Bit

Values

Definition

000
100

One word header; interrupt disable
One word header; interrupt enable

Refer to Table 5-10.

5-16

Table 5~10 Command Code and Mode Field Definitions
Command
Code
Field

Command
Name

00001

Read

Command
Mode
Field
0000
0001
0010
0011

Mode
Name
Read next (forward)
Read previous (reverse)
Reread previous (space reverse,
read two)
Reread next (space forward, read
reverse)

00100

Write
Characteristics

0000

Load message buffer address and
set device characteristics

00101

Write

0000
0010

Write data (text)
Write data retry (space reverse,
erase, write data)

00110

Write
Subsystem

0000

Normal (diagnostic use only)

01000

Position

0000
0001
0010
0011
0100

Space records forward
Space records reverse
Skip tape marks forward
Skip tape marks reverse
Rewind

01001

Format

0000
0001
0010

Write tape mark
Erase
Write tape mark entry (space
reverse, erase, write tape mark)

01010

Control

0000
0001
0010

Message buffer release
Rewind and unload
Clean (NOP on TU80)

01011

Initialize

0000

Drive initialize

01111

Get Status
Immediate

0000

Get status (END message only)

The swap byte bit in the command packet/header word (bit 12) instructs the M7454 to alter the sequence
of storing and retrieving bytes from the CPU's memory. When swap bytes = 1, an industry compatible
sequence (beginning with an even byte) is used. When swap bytes = 0, the swapping begins with an odd
byte. (This is so only for data transferring; it is ignored otherwise.)

5-17

Figures 5-7 and 5-8 indicate the memory positions for the bytes as they are read from or written on the
tape. In these examples, the bytes of data in the record block on tape are numbered starting at O. Byte 0 is
always the data byte at the beginning of the block (that is, the part of the block that is closest to BOT).

NOTE
When reading in reverse, the first data byte read is
the last data byte of the sequence written. The read
reverse command stores this first byte in the last
buffer position; the next byte in the next to last buffer position, etc. This results in having data put in
memory in the right order when reading the buffer
sequentially.
Command Packet Examples
Examples of the command packets and operational programming notes used in the TU80 Subsystem are
provided in this section. Refer to the figure corresponding to the command packet example you are interested in.

NOTE
All four words of the command packet are always
read in, even if the command takes only one word
(rewind) or two words (space). Thus, the command
packet must contain four words, and it must have
good parity because the transport rejects the command packet on the basis of errors in the unused
words.

SWAP BYTES = 0
BUFFER ADDRESS =
BYTE COUNT = 10(8)
BLOCK SIZE = 10(8) BYTES

1000

1002

1004

1006

SWAP BYTES = 1
BUFFER ADDRESS =
BYTE COUNT = 10(8)
BLOCK SIZE = 10(8) BYTES

1000

3
10001
1002

1004

1006

SWAP BYTES = 0
BUFFER ADDRESS = 1001
BYTE COUNT = 10(8)
BLOCK SIZE = 10(8) BYTES

SWAP BYTES = 1
BUFFER ADDRESS = 1001
BYTE COUNT = 10(8)
BLOCK SIZE = 10(8) BYTES

10001

1002

1006

1010

1004

1006

1010

10001
1004

1002

MA-2951

Figure 5-7

Byte Swap Sequence, Forward Tape Direction (Read or Write)

5-18

SWAP BYTES = 1
BUFFER ADDRESS
1000
BYTE COUNT = 10(8)
BLOCK SIZE = 10(8) BYTES

SWAP BYTES = 0
BUFFER ADDRESS = 1000
BYTE COUNT = 10(8)
BLOCK SIZE = 10(8) BYTES

3 021
10020 0
1

2 031
10020 0

1004

1006

SWAP BYTES = 0
BUFFER ADDRESS = 1001
BYTE COUNT = 10(8)
BLOCK SIZE
10(8) BYTES

SWAP BYTES
1
BUFFER ADDRESS = 1001
BYTE COUNT = 10(8)
BLOCK SIZE = 10(8) BYTES

10001

1002
2
1
10001
1004

1006

1010

1002

1004

1006

1010

10 0

SWAP BYTES = 0
BUFFER ADDRESS =
BYTE COUNT
7
BLOCK SIZE = 7 BYTES

SWAP BYTES = 1
BUFFER ADDRESS = 1000
BYTE COUNT = 7
BLOCK SIZE = 7 BYTES

0
10020 0
3 021
1

1000
1002

1004

1006

SWAP BYTES = 0
BUFFER ADDRESS
1001
BYTE COUNT = 7
BLOCK SIZE = 7 BYTES

SWAP BYTES = 1
BUFFER ADDRESS
1001
BYTE COUNT = 7
BLOCK SIZE
7 BYTES

1000

1002
1004
1006

10001

1
2

Figure 5-8

1002

1004

1006

6
MA·2952

Byte Swap Sequence, Reverse Tape Direction (Read)

Command Packet Example

Figure
Number

Get status
Read
Write characteristics
Write
Position
Format
Control
Initialize

5-9
5-10
5-11
5-12
5-13
5-14
5-15
5-16

5-19

Get Status Command - Figure 5-9 shows the get status command packet. This command causes an update
of the five extended status registers in the message buffer area. However, after the end of any command,
the TU80 hardware automatically updates the extended status registers. Therefore, this command need
only be used when the TU80 has been left idle for some time or when a status register update is desired
without performing a read, write, or position tape command.
Read Command - Figure 5-10 shows the read command packet. There are four modes of operation: read
forward, read reverse, reread previous, and reread next. In all cases a read operation is assumed to be for a
record of known length. Therefore, the correct record byte count must be known. If the byte count is
correct, normal termination occurs. If the record is shorter than the byte count, record length short (RLS)
sets and a tape status alert (TSA) termination occurs. If the record is larger than the byte count, record
length long (RLL) and tape status alert (TSA) are set. Also, any read operation that encounters a tape
mark does not transfer any data. In this case tape mark (TMK) and record length short (RLS) are set and a
tape status alert (TSA) termination occurs.
Read reverse operations that run into BOT cause Reverse Into BOT (RIB) to set and cause a tape status
alert (TSA) termination. Tape motion stops at BOT. Read reverse while at BOT causes a function reject
(NEF) status, with no tape motion.

NOTE
When reading reverse, the first data byte read is the
last data byte of the sequence written. The read
reverse command stores this first byte in the last
buffer position; the next byte in the next to last buffer position, etc. This results in having data put in
memory in the right order when reading the buffer
sequentially.
Write Characteristics Command - Figure 5-11 shows the write characteristics command packet. Its objective is to inform the TU80 Subsystem of the location and size of the message buffer in CPU memory
space. The message buffer must be at least seven contiguous words long and begin on a word boundary.

CTL

DEV.

DEP.

A
C
K

C
V
C

4
COMMAND

FMT 1

MODE

I
E

NOT USED
MODE: 0000 = GET STATUS (END MESSAGE ONLY)
NOTE:
SEE MESSAGE PACKET
EXAMPLES FOR DATA FORMAT.
MA·2956

Figure 5-9

Get Status Command Packet Example

5-20

DEV.

DEP.

A
C
K
A
1 •

C
V
C

0
P
P

S
W
B

4
COMMAND

FMT 1

MODE

I
E

LOW-ORDER
BUFFER ADDRESS

o•

HIGH-ORDER
BUFFER ADDRESS

BUFFER EXTENT
(BYTE COUNT)
(16 BIT POSITIVE INTEGER)

A
1
7

A
0
0
A
1
6
~

MODE: 0000= READ NEXT (FORWARD)
0001 = READ PREVIOUS (REVERSE)
0010 = REREAD PREVIOUS (SPACE REV, READ FWD)
0011 = REREAD NEXT (SPACE FWD, READ REV)
NOTE:
THE OPPOSITE BIT (OPP) ALTERS THE
EXECUTION SEQUENCE OF THE REREAD COMMAND
MODES, i.e., SPACE FWD, READ REV
BECOMES READ FWD, SPACE REV;
SPACE REVERSE, READ FORWARD BECOMES
READ REVERSE, SPACE FORWARD.

Figure 5-10

Read Command Packet Example

DEV.

DEP.

A
C

C
V
C

A
1 •

MA·2954

5
FMT 1

MODE

I
E'

COMMAND

LOW·ORDER
CHARACTERISTICS DATA ADDRESS

o •

HIGH·ORDER
CHARACTERISTICS DATA ADDRESS

•

BUFFER EXTENT
(BYTE COUNT)
(16 BIT POSITIVE INTEGER)

0
0
A
1
6

A
1
7

MODE: 0000 = LOAD MESSAGE BUFFER ADDRESS AND
SET DEVICE CHARACTERISTICS

CHARACTERISTICS DATA
A
1 •

LOW-ORDER
MESSAGE BUFFER ADDRESS

HIGH·ORDER
MESSAGE BUFFER ADDRESS

•

LENGTH OF
MESSAGE BUFFER
(16 BIT POSITIVE INTEGER)

o •

ol
I

(AT LEAST 14

0
0

1
7

1
6
~

BYTES LONG)

CHARACTERISTICS MODE BYTE

5.2.2.3
MA·2958

Figure 5-11

Write Characteristics Command Packet Example

5-21

The write characteristics command also transfers a characteristics mode word to the transport. This word
causes specific actions for certain operational modes. Table 5-11 defines the bits for this word.

If a good message buffer address has not been loaded with a write characteristics command, the need
buffer address (NBA) bit in the TSSR register sets.
The following concerns bit usage in the characteristics word.
Interrupts Enables - If interrupts are enabled (IE), interrupts may occur at any time. This is due to
the possibility of diagnostic interrupts and AC LO occurring immediately after normal terminations
(even if A TIN interrupts are not enabled). The software must therefore defend against unexpected
interrupts. The drive may not be usable, but the software still should not crash.
Attention Interrupts Enabled - With attention interrupts enabled, a nonfatal diagnostic failure is not
reported until control of the message buffer is returned to the transport. A fatal failure may interrupt
at any time as long as interrupt enable is set. It should also be noted that the drive could break in such
a way that interrupts may be issued even with IE reset.
Attention Interrupts Disabled - With attention interrupts disabled, a diagnostic failure is not noticeable until the next command is issued. At this time the command is rejected.
Table 5-11

Bit

Write Characteristics Data Bit Definitions
Name

15-08

Definition

Not used

ESS

Enable Skip Tape Marks Stop: When this bit is set, it instructs the transport to stop
during a skip tape mark command when a double tape mark (two contiguous tape
marks) has been detected. In the default setting of 0, the skip tape marks command
terminates only on tape mark count exhausted or if it runs into BOT.

ENB

This bit is only meaningful if the ESS bit is set. If the drive is at BOT, when a skip
tape marks command is issued and the first record seen is a tape mark, then the
transport sets LET and stops after the first tape mark. If the bit is clear, the drive
does not set LET but just counts the tape mark and continues.

EAI

Enable Attention Interrupts: When this bit is a 0, attention conditions, such as
off-line, on-line, and microdiagnostic failure, do not result in interrupts to the CPU. If
set to aI, interrupts are generated.
NOTE
Transport must own the message buffer, via message buffer release, to set attention interrupts.

03-00

ERI

Enable Message Buffer Release Interrupts: If this bit is 0, interrupts are not
generated when a message buffer release command is received by the transport.
Upon recognition of the command, only subsystem ready (SSR) is reasserted. If ERI
is aI, an interrupt is generated.
Not used

5-22

Write Command - Figure 5-12 shows the write command packet. There are two modes: write data and
write data retry (space, reverse, erase, write data). Each operation is straightforward and designed to transfer data onto tape in the forward direction only.
If a write command is executed at or beyond the EOT marker, a tape status alert (TSA) termination
occurs. EOT remains set until passed in the reverse direction or a subsystem initialize.
If a write command is executed anywhere and the identification burst (IDB) was previously written bad or
was not found when it left BOT, then density check (OCK) is set and tape position lost termination occurs.

Position Command - Figure 5-13 shows the position command packet. This command causes tape to space
records forward or reverse, skip tape marks forward or reverse, and to rewind to BOT. An exact tape
mark/record count must be the second word of the packet for skip tape mark and space record commands.
A space records operation automatically terminates when a tape mark is traversed. Also, record length
short (RLS) is set if the record count was not decremented to zero.

CTL

DEV.

DEP.

A
C
K
A
1 ..

C
V
C

S
W

FMT 1

MODE

I
E

COMMAND

LOW-ORDER
BUFFER ADDRESS

·0
0

HIGH-ORDER
BUFFER ADDRESS

BUFFER EXTENT
(BYTE COUNT)
(16 BIT POSITIVE INTEGER)

• 0

A
1

A
1
6

•

MODE: 0000= WRITE DATA
0010=WRITE DATA RETRY (SPACE REV,
ERASE, WRITE DATA)
MA-2959

Figure 5-12

Write Command Packet Example

CTL

DEV.

DEP.

A
C
K

C
V
C

I
E

MODE

FTM 1

TAPE MARK/RECORD COUNT
(16 BIT POSITIVE INTEGER)

COMMAND

•

MODE: 0000 = SPACE RECORDS FORWARD
0001 = SPACE RECORDS REVERSE
0010= SKIP TAPE MARKS FORWARD
0011 = SKIP TAPE MARKS REVERSE
0100 = REWIND (RECORD COUNT IGNORED)
MA-2961

Figure 5-13

Position Command Packet Example

5-23

A skip tape marks command terminates when it encounters a double tape mark and the enable skip stop
mode is specified (ESS bit set) in the characteristics word. Termination also occurs if a tape mark is the
first record off BOT and ESS and ENB bits are set in the characteristics word. Record length short (RLS)
is set if the record count is not decremented to zero.
A space records reverse or skip tape marks reverse (which runs into BOT) sets reverse into BOT (RIB) and
causes a tape status alert termination.
NOTE
If the tape is positioned between BOT and the first
record and you do a space reverse or skip reverse,
RIB sets and the residual frame count equals the
specified count in the original command.
Format Command - Figure 5-14 shows the format command packet. This command can write a tape
mark, rewrite a tape mark, and erase tape. In all cases, executing a format command at or beyond EaT
causes a tape status alert (TSA) termination. The EaT bit remains set until passed in the reverse direction.
A subsystem initialize can also reset the EaT bit. Also, any format command executed with density check
(OCK) set causes a tape position lost termination.
Density check is set when an invalid identification burst (lOB) is read off BOT. This occurs in a read-afterwrite mode within the first three inches of tape and is transparent to the user's operation.
The erase command causes three inches of tape to be erased. This length is controlled automatically by the
transport hardware. Successive erase commands can be used to erase more than three inches (in three inch
increments ).
Control Command - Figure 5-15 shows the control command packet. The three modes of operation are
message buffer release, unload, and clean. The message buffer release command, when executed with the
ACK bit set, allows the transport to own the message buffer so it can update the status in the message
buffer area on an ATTN. This is beneficial when the operating system is processing data in other areas not
concerned with operating the TS 11 Subsystem and the host wants to know the current drive status.
The unload command is designed to rewind tape completely onto the supply reel. When the command is
executed, termination occurs immediately; an interrupt occurs if IE is set.
The clean tape command is a No-Op in the TU80 and immediately returns a normal termination code and
message packet.
Initialize Command - Figure 5-16 shows the initialize command packet. This command is not very useful,
but is included for compatibility with packet protocol. A drive initialize can be done by a write to the
TSSR, as this action does not need a command packet.
The drive initialize command is a no-op. It results in a message update, just like a get status, if there are no
microdiagnostic or runaway errors. However, if errors are displayed, the command does the same thing as a
write to the TSSR. Section 5.1.3 contains TSSR details.

5-24

DEV.

DEP.

A
C
K

C
V
C

FTM 1

MODE

I
E

COMMAND

NOT USED
MODE: 0000 = WRITE TAPE MARK
0001 = ERASE
0010 = WRITE TAPE MARK RETRY (SPACE REV,
ERASE, WRITE TAPE MARKl
MA-2962

Figure 5-14

Format Command Packet Example

15'

CTL

DEV.

DEP.

A
C
K

C
V
C

FMT 1

MODE

COMMAND

NOT USED

MODE: 0000 = MESSAGE BUFFER RELEASE
0001 = UN LOAD
0010 = CLEAN TAPE
MA-2960

Figure 5-15

Control Command Packet Example

CTL

DEV.

DEP.

A
C
K

C
V
C

11
MODE

4
COMMAND

FMT 1

I
E

NOT USED
MODE: 0000= DRIVE INITIALIZE
MA-2963

Figure 5-16

Initialize Command Packet Example

5-25

Message Packet/Header Word
Figure 5-17 shows the first message packet/header word and Table 5-12 defines it.

CLASS
CODE

RESERVED

CTL

ACK

4
MESSAGE
CODE

PACKET
FORMAT 1
C

M
MA-2955

Figure 5-1 7

Message Packet First Header Word

Message Packet First Header Word Bit Definitions

Table 5-12
Bit

Name

Function

Acknowledge

This bit is used by the M7454 to inform the CPU
that the command buffer is now available for any
pending or subsequent command packets. On an ATTN
message, this bit does not set since the drive
does not own the command buffer.

14-12

Reserved

These bits are reserved for future expansion.

11-8

Class
Code
Field

These bits define the class of failures found in
the rest of the message buffer.

7-5

Packet

Format
#1 Field

4-0

MSG
Type

Class
Value

ATTN
ATTN
FAIL
FAIL
FAIL

0000
0001
0000
0001
0010

FAIL

0011

Definition
On- or off-line
Microdiagnostic failure
Packet bad
Other (lLC, ILA, NBA)
Write lock error or non-executable
function
Microdiagnostic error

The single value supported by the TU80 is as
follows.

Value

Definition

000

One word header

Term Class

Value

Definition

0,2

10000
10001
10010
10011

End
Fail
Error
Attention

Message
Code

3
4,5,6,7
1,7

5-26

Message Packet Example
All message packets are identical. Each message packet contains the message packet/header word just
described, plus a data length field word and the five extended status registers. Figure 5-18 shows the message packet format.
OPERATIONAL INFORMATION
The following information considers the operation and programming requirements of the TU80
Subsystem.
UNIBUS Registers
Each TU80 has two UNIBUS word locations used as device registers. The base address, when written to, is
the data buffer register (TSDB). When read, it is the bus address register (TSBA). The second device
register (base address + 2) is the status register (TSSR). Writing to the TSSR causes a subsystem initialize
command, and reading the TSSR reads device status.
The TSDB register is the only register written to during normal operations. DATO or word access must be
used to properly write command pointers to the TSDB. DATOB or byte access to the TSDB causes maintenance functions.
Commands are not written to the transport's UNIBUS registers. Instead, command pointers, which point
to a command packet somewhere in CPU memory space, are written to the TSDB register. The command
pointer is used by the transport to retrieve the words in the command packet. The words of the command
packet tell the transport the function to be performed. They also contain any function parameters such as
bus address, byte count, record count, and modifier flags.

CTL

DEV.

STAT

STD.

A
C

FMT 1

STATUS

MESSAGE

RBPCR

XSTATl
XSTAT2

XSTAT3
MESSAGES:
BITS 4:0

10000 = END
10001 = FAIL
10010 = ERROR
10011 = ATTN

STD STATUS:
BITS 11:8

FAIL MSG.
0000 = SERIAL BUS PARITY ERROR
0001 = OTHER
0010 = WRITE LOCK ERROR OR NON·EXECUTABLE FUNCTION
0011 = MICRODIAGNOSTIC FAILURE
ATTN MSG
0000 = ON OR OFF LINE
0001 = MICRODIAGNOSTIC ERROR
MA·2964

Figure 5-18

Message Packet Example

5-27

Command and Message Packets
Command packets must reside on modulo-4 address boundaries within CPU memory space. This means
the starting address of the packet must be divisible by 4 (that is, octal 00, 04, 10, 14, etc.).
All four words of a command packet must exist and have good memory parity, even if all four words are
not used by a command. (For instance, rewind uses only one word.)
Message packets are issued by the subsystem and are deposited into the CPU's memory space. Controlled
operation of the TU80 requires that it be supplied a message buffer address on a write characteristics
command. The five extended status registers are stored in this message buffer area. The END message
packet, which results at the end of any command, contains these extended status words.
Special Conditions and Errors
Table 5-13 includes the meanings of the binary values within the termination class code field in the TSSR
register.

Table 5-13 Termination Class Codes
TC2-0
Value

Msg
Type

Offset

Meaning

END

Normal Termination - This bit indicates the operation completed without
incident.

ATTN

Attention Condition - This code indicates that the transport has undergone a
status change: going off-line, coming on-line, or a microdiagnostic failure.

END

Tape Status Alert - This bit indicates a status condition has been encountered
that may have significance to the program. Bits of interest include TMK, EaT,
RLS, and RLL.

FAIL

Function Reject - This bit indicates the specified function was not initiated. Bits
of interest include OFL, VCK, BOT, WLE, ILC and ILA.

ERR

Recoverable Error - This bit indicates tape position is one record beyond what
its position was when the function was initiated. Suggested recovery procedure is
to log the error and issue the appropriate retry command.

ERR

Recoverable Error - This bit indicates tape position has not changed. Suggested
recovery procedure is to log the error and reissue the original command.

ERR

Unrecoverable Error - This bit indicates tape position has been lost. No valid
recovery procedures exist unless the tape has labels or sequence numbers.

ATTN/
ERR

Fatal Subsystem Error - This bit is not used.

5-28

Status Error Handling Notes
TSSR error bits, other than the fatal class, termination class, and SC bits, are cleared by loading a command pointer into the TSDB register. SC is reset if it is due to a TSSR error (RMR or NXM). Extended
status error bits are cleared after the END message is sent.
All commands (even get status command) clear the XST AT error bits; except XST AT3 bits 15 through 8
(transport error code) and bit LXS are not cleared.
If a density check condition is detected during a read, space, or skip function, the DCK bit is set, but the
operation is not stopped. If DCK is the only status bit set during the operation, normal termination is
reported. This allows tapes with good data but bad density check areas to be read. If a wrong density tape
has been mounted, other errors are reported and the operation stops. Note that if only the density check
area is bad, the density check indicator on the drive's operator panel goes on, even though the data records
might be the correct density. The DCK indicator stays on until BOT is encountered again or until a subsystem initialize is performed. Note that if you begin reading a tape, get a density check condition with no
other errors, then append to the tape; the write gets a termination class code of 6. This indicates that the
tape position is lost because density check remains set. The whole tape should be copied over so that drives
depending on the IDB will be able to read the tape.
A command is not responded to while another command is in progress (result is RMR), except in the
following cases.
1.

A DATa (word access) to the TSSR (subsystem initialize) brings any operation in progress to an
immediate halt. All subsystem parameters that had been in the subsystem's memory (VCK
reset, EaT, etc.) are erased. Also, if the on-line switch is on, the drive performs an auto-load
sequence and positions the tape at BOT.

The transport responds to any nontape motion command while performing a rewind unload
(while the drive is off-line) because SSR is still up.

The transport also responds to any nontape motion commands (get status, drive initialize, set characteristics, and message buffer release) when off-line, except when in maintenance mode. (The subsystem ready
command, SSR, is not asserted in this case and results in RMR.)
The following failures can occur without resulting in an interrupt, even though the specified command had
interrupt enable set.
NXM
BPE

They might occur before the interrupt enable bit
is fetched as part of the command packet.

These cases may result in a hung controller (SSR does not come up again until a subsystem initialize).
M7454 Failure
If a host incurs difficulties in configuring a TU80 into the system, or a host could not access a TU80 during
a normal on-line opreation, the M7454 may be at fault. Look for an appropriate message on the operator's
terminal and in the system error log. Also, refer to Chapter 6 of this manual under "UNIBUS Adapter
Module Diagnostic," the applicable Diagnostic Listings and CPU handbooks.

5-29

OPERATIONAL DIFFERENCES
The following describes three differences in the operation of the TU80 Subsystem compared to earlier
DECmagtape products.
1.

The skip tape marks (files) function is implemented in the hardware on this subsystem. Earlier
DECmagtapes had this function emulated by the software driver through use of the space
records command.

If a space records command is issued while positioned at or beyond EOT, the operation is not
terminated after one record has been traversed. The termination criteria remains the same as for
any other location on tape; that is, record count exhausted or tape mark encountered. The skip
tape marks command operates in the same manner. EOT is not allowed to alter its operation.

A skip files command could take 15 to 20 minutes to complete to the end of a 2,400 foot reel of
tape. There is no abort procedure other than a subsystem initialize. This causes an automatic
load sequence.
NOTE
As a debugging aid, set the message buffer to all Is
(ones). This eliminates any confusion that might be
caused by earlier messages.

5-30

CHAPTER 6
INSTALLATION

SITE PLANNING
Space Requirements
Figure 6-1 shows the transport dimensions and the space and service clearances required for the TU80
cabinet model H9643. There must be enough space to open the front, rear, and top doors.
Power Requirements
The TU80 tape transport can be operated within 93 to 128 Vac, 60 Hz (120 Vac nominal) or 187 to 256
Vac, 50 Hz (220 or 240 Vac nominal). Frequency should not vary more than ±3 Hz (refer to Table 1-2).
The appropriate power plugs are provided with the transport (for plug's NEMA numbers refer to Table
1-2).

REAR
DOOR
/'

/
/

r
1129[ ~

51 IN
(129.5cm)

J731N

57 IN.
(143cm)

(185. 5cm)

51 IN

I
/

41.71N
(105.8cm)

L,~
L

21 .5IN
(54.6cm)

/
/'
,,/

FRONT
DOOR
TOP VIEW

-J
FRONT
VIEW
MA·0089·82

Figure 6-1

TU80 Space Requirements

6-1

The UNIBUS adapter module (M7454) typically draws 4.0 A at +5 Vdc. No other voltage is required.
Power for the module is derived from the host CPU through dedicated pins of the CPU backplane.

Environmental Requirements and Limits
The TU80 transport should be located in an area free from excessive dust, dirt, corrosive fumes and vapors.
The bottom of cabinet and air vents on the doors must not be obstructed. The operating environment
requirements are listed in Table 1-2.
Tools Required
5/32 inch allen wrench
3/4 inch combination box and open-end wrench
7/16 inch open-end wrench
9/16 inch open-end wrench
5/16 inch nut driver
Number 2 phillips screwdriver

UNPACKING AND INSPECTION
Floor Loading and Routing
The TU80 transport is shipped in a cardboard container and is mounted on a wooden skid. The shipping
weight is 147 kg (325 lb). ~heck the route the unit will travel to the installation site to guarantee problemfree delivery. The TU80 transport net weight is 127 kg (280 lb).
Unpacking
Figure 6-2 shows the unpacking procedure. Refer to numbered instructions on Figure 6-2.
To unpack the transport proceed as follows.
1.

Cut and remove the shipping straps around the cardboard container (1).

Lift and remove the top container cover (2).

Carefully lift and remove the two ramps from the top of the cabinet. Set them aside for future
use.

Lift and remove the protective carton (3).

Remove the top pad and polybag (3).

Remove the rear stabilizer package from the rear of the cabinet.

6-2

COVER

RAMPS

Figure 6-2

Unpacking a Transport

6-3

Securely attach the two ramps to the skid deck using Figure 6-3 as a guide. Engage the ramps in
the groove matching the arrows.

Use a 9/16 inch wrench to unbolt and remove four shipping bolts and shipping brackets (Figure
6-3).
NOTE
The process of deskidding or taking the cabinet off
the pallet (skid) occurs next. EXTREME CARE
MUST BE TAKEN!
CAUTION
The cabinet can be rolled only when the leveler feet
are raised.

MA-0091-82

Figure 6-3

Removing a Transport from a Skid Using the Supplied Ramps

6-4

Roll the TU80 toward the ramp-attached side of the skid by pushing gently on the rear side of the
cabinet.

10.

Gently slide the cabinet forward on the ramps. Hold the TU80 firmly to prevent it from tipping.
Allow it to roll off the skid, down the ramps and onto the floor.

11.

Remove the wooden ramps. Store the skid, ramps, and carton for future use.

Inspection
After removing the TU80 transport from its container, inspect it and report any damage to the responsible
shipper and the local DIGITAL sales office.
Inspect the TU80 as follows.
1.

Inspect all panels, doors, door latches, and control panel for any obvious damage.

Using a 5/32 inch allen wrench, open the front and rear doors. Inspect the cabinet for any foreign
material, loose or damaged components or cables.

Pull the top cover latch and lift the top cover. Inspect the tape deck for broken glass, damaged
magnetic head components, and damaged reels.

Check for any foreign materials that may have lodged in the tape reels. Rotate the supply and takeup reels.

Check the tape path for any sharp edges. Close the top cover, the front and rear doors.

OPERATION PREPARATIONS
Place the TU80 transport not further than 2.7 m (9 ft) from the host CPU and with adequate space clearances
(Figure 6-1) for air circulation and servicing. Connect the transport to the CPU by the power switching wire
and two shielded interface cables. Power it on.
TU80 preparations for operation are performed as follows.

Mechanical Installation
1.

Roll the transport to its correct location.

Open the rear door and remove the cardboard box with the TU80 Accessory Kit (TU80K-AC).

Remove two screws holding the shipping bracket (Figure 6-4) to the frame stabilizing bar.

Tum the shipping bracket around to its normal (TU80 operating) position and secure it with the
two mounting screws.

Mechanical installation procedure depends on the TU80 cabinet configuration - with or without a disk drive.

NOTE
Return the shipping bracket to its original shipping
position before reshipment.

6-5

FRAME
STABILIZING
BAR

MA·0915·83

Figure 6-4 Reversing the Rear Shipping Bracket

6-6

If there is a disk drive in the TU80 cabinet, proceed as follows.

Install the extension stabilizer (PN H9544-HC) (Figure 6-5).
a.

Unwrap the stabilizer and mounting hardware.

Slide the stabilizer in place from rear of the cabinet.

Fasten the tether cable to the stabilizer using the supplied hex screw.

Thread on the stabilizer's leveling foot.

Lower four leveler feet as shown in Figure 6-6.
a.

Lower the leveler foot to contact the floor.

Using a 3/4 inch open-end wrench, tum the top nut up to top and tighten it.

Repeat for the remaining feet to stabilize the unit.

Continue with' 'Electrical Connection. "

TETHER CABLE

II
.~

EXTENSION STABILIZER

I~
~
~

FRONT

fl.®

UNTAPE TETHER CABLE FROM BASE
AND FASTEN TO STABILIZER

LEVELER
FOOT
MA-0092-B2

Figure 6-5

Cabinet Leveler Feet Assembly and Extension Stabilizer

6-7

TO LOWER A FOOT

TO RAISE A FOOT

MA·0093C·82

Figure 6-6

Leveler Feet Adjustments

6-8

If there is not a disk drive in the TU80 cabinet, proceed as follows.

Remove two end (side) panels and the rear door as shown on Figure 6-7.
a.

Pull up the spring pins and remove the rear door (Figure 6-7a). Remove the ground strap
using a 5/16 inch nut driver.

Remove the door hinge brackets located in the rear bottom left and right corners of the cabinet using a 7/16 inch open-end wrench (Figure 6-7b).

Remove the end panels by lifting them up and away from the unit.

Remove the ground straps from the side (end) panels, using a 5/16 inch nut driver.

Remove two rear leveler feet (Figures 6-5 and 6-6).
a.

Using a 3/4 inch open-end wrench, loosen and lower the top nut on a foot.

Place a 9/16 inch open-end wrench on the bottom nut on a foot and turn the nut upward.

Back the foot off the floor, then pull it outward to remove.

REAR DOOR REMOVAL

END PANEL REMOVAL

@ BOTTOM PANEL REMOVAL

II)

MA-009ol-S2

Figure 6-7

Cabinet Assembly

6-9

Install the rear stabilizer PN H9544-MJ (Figure 6-8).
a.

Install two couplers in the stabilizer base.

Slide the stabilizer under the rear bottom of the cabinet so that the couplers are directly under
the mounting slots.

Install the rectangular washers, retaining washers and hex screws. Do not tighten the screw
yet.

Level the cabinet by adjusting the couplers. Use a screwdriver inserted into a hole in the coupler to jack it up.
NOTE

To raise the cabinet, turn the coupler counterclockwise. To lower the cabinet, turn the coupler
clockwise.
e.

Slide the shim(s) in place in the mounting slots.

Tighten the hex screw(s) using a 3/4 inch box wrench and number 2 phillips screwdriver.

11111111111

* MA Y NOT BE USED
MA-0095-82

Figure 6-8

Rear Stabilizer Installation

6-10

Adjust the leveler feet to completely stabilize the cabinet (Figure 6-6) using the 3/4 inch and 9116 inch openend wrenches.
Replace the end panels and the rear door on the cabinet and re-attach the ground straps.

NOTE
If you need to move the transport to another loca-

tion within the room, raise the leveler feet. Release
the nuts on the feet using the 3/4 inch and 9/16 inch
open-end wrenches (Figure 6-6). Then pull each
foot up to top.
Electrical Connection
NOTE
Check the TU80 data (ID) plate for power specifications. Make sure that the local line voltage and
frequency are compatible with the transport power
specifications.
1.

Check that the power ON/OFF circuit breaker on the 874 power controller is in OFF position, and
the REMOTE/LOCAL switch is set to REMOTE position (Figure 6-9).

Connect the remote power switching cable from the 874 power controller (any of the four connectors) to the CPU power controller. Turn CPU's circuit breaker OFF.

Check that the power cable from the transport power supply is plugged into the ac connector on
the power controller.

MA-0096-82

Figure 6-9

874 Power Controller

6-11

Plug the power cord into a local power outlet. Turn the circuit breaker on the 874 power controller
to ON.
NOTE
Refer to power specifications in Table 1-2.

Open the TU80 top cover and set the power switch in ON (1) pressed position.

Tum CPU power on. The LOGIC OFF indicator on the TU80 control panel should go on.
NOTE
When installed, the TU80 should be in the remote
power-on mode controlled by the CPU.

Tum CPU power off. Now proceed with the M7454 UNIBUS adapter installation and interfacing
the TU80 with the CPU.

Grounding
The TU80 transport is grounded through the ground line in the power cable. No other grounding is needed.
UNIBUS ADAPTER MODULE INSTALLATION AND INTERFACE CABLING
The M7454 UNIBUS adapter module is a standard quad-height module and is positioned in a small peripheral controller (SPC) slot of the host computer backplane. The M7454 is connected to the TU80 transport by a
set of internal and external interface cables. Cable interconnections are shown on Figures 6-10 through 6-12.
Figure 6-11 shows the plug-to-plug connections of all 110 cables.
Turnkey Configuration
If the TU80 is provided with the host system, the M7454 module and CPU internal (ribbon) cables may
already be installed in the SPC slot. If so, the TU80 transport is ready for external cabling to the CPU.
NOTE
Check for the CPU Kit (TU80K-CP). If it is
shipped with the transport, the M7454 module has
to be installed in the CPU. Call for the authorized
Field Service Representative to do this installation.
Refer to the installation procedures under "AddOn Configuration."

6-12

EXTERNAL
INTERFACE
CABLES
(BC17N·12)

MA-0097-82

Figure 6-10

Typical Interface Cabling

FEMALE

(HOST CPU- -, SHIELDED

I
I
I
I
I

MALE
P3

fTAPE TRANSPORT'

I
I (ROUND)
INTERFACE MALE
CABLES

FORMATTER/
CONTROL
MODULE
P4

---..-............n.a

I
I

P5
S2
FEMALE

L - - - ....1

'-----_ ...I

Figure 6-11

MA-0409-82

Plug-to-Plug Connections of 110 Cables

6-13

TU80 External Cabling
NOTE
External cabling is a user-oriented procedure that
does not require special training.
1.

Open the rear door of the TU80.

Route two external interface cables (PN BC17N-12) already installed in the TU80 to the designated bulkhead connectors on the CPU VO frame. Secure each external plug in the bracket (and in the
internal cable c,onnector) with two flat-head screws as shown in Figures 6-10 and 6-16.
NOTE
In configurations with three or four TU80s on one
CPU, 24 ft external cables (PN BC17N-24) must be
used.

Close the rear door of the TU80 cabinet.

Now continue with the TU80 Acceptance Diagnostics.

Figure 6-12

Installation of External Cables in TU80 Tape Deck

6-14

Add-On Configuration
If the TU80 is used as an add-on to the host system, the M7454 module has to be installed in the CPU using
the CPU Kit (TU80K-CP), provided with the transport.

M7454 Preparation and Installation - The following procedure is for preparing and installing the M7454.
NOTE
The following procedures must be performed by an
authorized DIGIT AL Field Service
Representative.
1.

Remove the M7454 module, cables, bulkhead connector plates, frame, and mounting hardware
from the shipping container. Unwrap and examine them for any physical damage.

On the M7454 adapter module, select the proper UNIBUS address, interrupt vector and word
burst using a single 10-position DIP switch in the location 20C (Figures 6-13 and 6-14).

NOTES
If this is the first TU80 on the host CPU, skip
step 2 since the settings on the M7454's DIP
switch are factory-set.
The typical UNIBUS address and vector for a
single TU80 Subsystem configuration are
specified in Table 6-1.
When more than one (up to four) of the TU80
Subsystems are installed with the host system,
the UNIBUS addresses and vectors are selected according to Table 6-2.

Switch positions 1 to 7 are used to select vector
bits 8 to 2. Switch position 8 is used to select
two-word or four-word burst size. TU80 uses
two-word burst size. Switch positions 9 and 10
are used to determine a transport number and
the corresponding UNIBUS address.

Check the jumpers in Location 4F on the module. Jumpers JPll, JPI2, JPI3, and JP14
select the UNIBUS address range. The standard starting address is 7725228 selected by
JPll, which is etched on side two of M7454. If
another address range is required, cut JPll
and install JP12 (for address range starting at
772722), JP13 (777362), JP14 (777422).

6-15

REFERENCE
EDGE

DIP
SWITCH

1-0
2CJ-

3-D

4 --;:::)

506-0

c::r-

7
8 --;:::)
9 --;:::)

10-0
OFF

20C

JP12 JP11

ooi/

JP14./JP13?OO

MA-Ol06-82

Figure 6-13

UNIBUS Adapter Module and 1/0 Internal Cables

VECTOR BITS
ON

I,811161;51141~311211Iil

OFF
SWITCH
POSITIONS

___
2_ _ _
3_ _

4 _ _5_ _ _6_ _ _- J

VECTOR
SELECT

ADDRESS
SELECT
BURST
SIZE *

* ON - 2 WORDS
OFF - 4WORDS
EXAMPLE: SWITCH HBIT 8) IS IN ON POSITION
MA-Ol07-82

Figure 6-14 DIP Switchpack Setting for a Single TU80 Configuration
(Address 172522, Vector 224)

6-16

Table 6-1

Single-TU80 Address Selection

Unit
Number
0

Address

Vector

SW.9

SW.I0

1725228
F52216

224 8
94 16

Table 6-2 Address Selection in Multi-TU80 Configuration

Transport

Unit
Number
0

Address

Vector

SW.9

SW.I0

Configuration

1725228
F55216

224 8
94 16

1 (Unit 0)

1725268
F55616

float *

OFF

2 (Units 0,1)

1725328
F55A16

float *

OFF

3 (Units 0,1,2)

1725368
F55E16

float *

OFF

4 (Units 0,1,2,3)

* Floating vector - 300 to 7008.
3.

Remove the G727 bus grant card from the desired SPC slot. Remove the nonprocessor grant
(NPG) jumper (cut CA 1 to CB 1) from the backplane of the same SPC slot.

Plug two internal flat ribbon cables (N OT KEYED CONNECTORS) into the Jl and J2 edge connectors on the M7454 module (Figure 6-13). Plug the cable(PN 70-19922) with the male external
connector into Jl and the cable (PN 70-19923) with the female external connector into J2 on the
board (Figure 6-11).
NOTE
The blue stripes on the flat cables must be on the
left side when you are facing the M7454 component
side.

Carefully insert the M7454 module into the SPC slot.

CPU Internal Cabling - Examine the CPU for compliance with the FCC installation specifications.
According to the FCC requirements, the CPU should have the 110 bulkhead connector frame at the rear bottom of its cabinet.
Follow the flowchart (Figure 6-15) and use the applicable procedures.

6-17

PROCEDURE A

PROCEDURE B

~
INSTALL M7454 IN
SPC SLOT

INSTALL I/O PANEL
PIN 74-26407-12 ON
CPU BULKHEAD
FRAME

INSTALL 1/0 PANEL
PIN 74-26407-12
INTO I/O FRAME
PIN 74-27292-01
INSTALL THIS 110
FRAME ON CPU RACK

ROUTE RIBBON 110
CABLES THRU
CABINET AND INSERT
CABLE CONNECTORS
INTO I/O PANEL
SLOTS

CONNECT EXTERNAL
SHIELDED INTERFACE
CABLES TO I/O PANEL
CONNECTORS
CONNECT EXTERNAL
CABLES TO TU80
MA-0108-82

Figure 6-15

TU80 Interface Cabling Flowchart

6-18

Procedure A
1.

Prepare and install the M7454 module as described above in "M7454 Preparation and
Installation.' ,

Install the I/O panel (PN 74-26407-12) on the CPU's I/O bulkhead frame at the bottom of the CPU
cabinet (Figure 6-16a).
Secure the I/O panel with two screws.

Route the internal I/O ribbon cables from the M7454 module through the CPU cabinet to the CPU
frame and insert the cable connectors into the slots on the I/O panel.

Proceed with external interface cabling.

NOTE
Use care not to chafe the internal cables against
other modules and chassis parts.

110 PANEL
(74-26407-12)

ROUND
INTERFACE
CABLE

RIBBON I/O
CABLE

110 BULKHEAD
FRAME (CPU RACK)

110 PANEL
(74-26407-12)

I/O FRAME
\ 74-27292-01)

MA-0109-82

Figure 6-16

110 Bulkhead Connector Panel and Frame

6-19

Procedure B
1.

Prepare and install the M7454 module as described above
Installation. ' ,

Mount the 110 panel (PN 74-26407-12) on the 110 frame (PN 74-27292-01) and secure with two
screws (Figure 6-16b).

Install the 110 frame (with 110 panel) on the CPU rack. Find the best location in the CPU rack to
accommodate internal and external interface cabling.

III

"M7454 Preparation and

NOTE
The recommended location for the 1/0 frame is at
the rear bottom of the CPU cabinet.
4.

Route the internal 110 ribbon cables from the M7454 module through the CPU cabinet to the CPU
frame and insert the cable connectors into the slots on the 110 panel.

Proceed with external interface cabling.

TU80 ACCEPTANCE DIAGNOSTICS
This section lists and describes all tests necessary to properly check and accept the TU80 Subsystem.
TU80 acceptance testing includes the following resident and host diagnostics.
Resident Diagnostics

Power-on Health Check
Basic Operator Diagnostic Test (Test 01)
UNIBUS Adapter Module Resident Diagnostic
Host Remote Diagnostics

PDP-II Front-End Diagnostic
PDP-II Data Reliability Diagnostic
VAX Front-End Diagnostic
VAX Data Reliability Diagnostic

NOTE
Refer to the Diagnostic Documentation of the
installed DIGIT AL computer for the applicable
information on· how to run and interpret the host
diagnostics.

6-20

Power-On Health Check
NOTE
Make sure that the TU80 power cord is plugged in
and the transport is energized (the power switch is
ON) before starting the acceptance tests.
This microdiagnostic (resident) test is performed when the TU80 is powered up by pressing the LOGIC ON
switch. If this check is successful, the LOGIC OFF indicator turns off and the two-digit display momentarily
shows 00. Then the BOT, RESET, ON-LINE, DIAGNOSTIC and SELECT indicators go on momentarily.
The LOGIC ON and FILE PRO indicators go on and stay on. Otherwise, a fault code is indicated on the twodigit display. Press the RESET, LOGIC OFF and LOGIC ON switches to repeat the check. If the fault code
reappears, proceed with fault isolation and the appropriate service actions.
Basic Operator Diagnostic Test 01
This test performs various tape motion and read/write exercises to verify transport operation.
With a 2400-foot reel of good, known-quality tape it takes approximately 10 minutes to run the test to completion. For test description, refer to Chapter 3 of this manual.
UNIBUS Adapter Module Resident Diagnostic
The M7454 UNIBUS Adapter Module performs its own internal diagnostic routine at the system power-up.
To run this diagnostic, tum the CPU's circuit breaker OFF/ON. The M7454 diagnostic resides in the onboard programmable ROM. It checks only the M7454 module without any tape motion or interface testing.
The diagnostic checks the M7454's microprocessor, sequencer, data paths, and buffer area. The test has
completed successfully when the LED indicator on the module goes on (Figure 6-13).
M7454 Status Checking - Refer to the following paragraphs for M7454 status checking.
TUBO Turnkey Configuration/Installation
When the M7454 (and TU80) fails during new system configuration (PDP-II or VAX), the host configures
around the TU80 not recognizing it. An appropriate error message appears on a computer console terminal.
TUBO Add-On Configuration/Installation

If a TU80 is added to a PDP-II system, the host system must be reconfigured by an operator using
an applicable SYSGEN routine. If the M7454 fails during SYSGEN, the host will be unable to get
through to the TU80, and an appropriate error message is displayed on the console terminal.

If a TU80 is added to a VAX system, the host automatically configures the unit into the system. If
the M7454 fails at that time, the host is unable to access the TU80, and an appropriate message
appears on the terminal.

On-Line Operation Failure
If the M7454 fails during normal on-line operation, the host is not able to continue to access the TU80. The
error message is entered in the system error log. When the operator tries to recall the TU80, the appropriate
error message appears on the operator's terminal indicating the "not found" status of the device and the time
and status at the time of failure.

To check the TU80 operating condition and to localize the failed module, reset the unit and perform the system power-up host to run the M7454 internal diagnostic. Then place the TU80 on-line and try to access the
transport through the host. If the fault condition persists (self-test LED does not come on), call Field Service.

6-21

To check the TU80 operating condition and to localize the failed module, reset the unit and perform
the host system power-up to run the M7454 internal diagnostic. Then place the TU80 on-line and try
to access the transport through the host. If the fault condition persists (self-test LED does not come
on), call Field Service.
PDP-II-Based Remote Diagnostics
PDP-II Front-End Diagnostics CZTUW, CZTUX, CZTUY, CZTUZ - This four-part complex test
checks the subsystem in all basic modes of operation and tests the interface bus, I/O silo, and TU80 transport's logic.
CZTUW
TST: 001
TST: 002
TST: 003
TST: 004
TST: 005
TST: 006
TST: 007
TST: 008
TST: 009
TST: 010
TST: 011

Ini tialize # 1
RAM Test
Command Reject Test
Write Characteristics Test
Volume Check
Completion Interrupt Test
Basic Packet Protocol Test
Non-Tape Motion Command Test
DMA Memory Addressing Test
Initialization After Write Characteristics Test
Basic Write Subsystem Memory Test

CZTUX
TST: 001
TST: 002
TST: 003
TST: 004
TST: 005
TST: 006
TST: 007
TST: 008

FIFO Exercizer Test
Initialize #4 Test
Off-Line Reject and Rewind Test
Basic Write Data Test
Basic Read Data (Forward and Reverse) Test
Manual Intervention Test
Configuration Typeout Test
Scope Loops Test

CZTUY
TST: 001
TST: 002
TST: 003
TST: 004

Space Records Test
Rereads Test
Write Data Retry Test
Write Tape Mark Test

CZTUZ
TST: 001
TST: 002
TST: 003
TST: 004
TST: 005
TST: 006

Write Tape Mark Retry Test
Skip Tape Marks Test
No-Op and Initialize Test
Erase and Operation Incomplete Test
Test of Operation at EOT Test
Function Tuning Test

6-22

PDP-II Data Reliability Diagnostic (CZTUV) - This test simulates a typical customer operating
environment and check data integrity when operating in both the start/stop and streaming modes. It is
mainly a data confidence test.
Data Reliability Program Tests
Basic Functions
Data Reliability
Streaming Test
Write Compatability /Write Utility
Read Compatability /Read Utility
Operator Selected Sequence

Test 1 :
Test 2 :
Test 3 :
Test 4:
Test 5 :
Test 6 :

NOTE
For Program Control Flags, refer to Diagnostic
Listing.
Operating Instructions for PDP-II-Based Diagnostics
Follow this procedure when using PDP-II-based diagnostics.
1.

Load XXDP + monitor
a.

Enter date

Answer hard core questions.
a.
b.

50 Hz? Y or N
LSI? Y or N
This is XXDP +. Type H or H/L for details (Help File).
[Receive XXDP + prompt (dot)]
e

Enter R (space) program name.
The program may be CZTUV or CZTUW, CZTUX, CZTUY, CZTUZ.
The operator entry should look like this.

[e R ZTUV??]
4.

Receive DR> prompt.

6-23

Enter the appropriate command.
For example,
DR>STA to start the test.

Change HW(L)? 'V' or 'N' - To run the diagnostic, the answer must be 'Y'.

Change SW(L)? 'V' or 'N'
NOTE
Refer to the Diagnostic Listing for specific program
problems and instructions.
No hard errors are allowed.

Hardware Parameters - The following are the TU80 base address and vector assignments.
TSSR ADDRESS (172522)?
VECTOR (224)?
Example of
commands:

STA/TES:2/FLA : IDU : LOE

Example
meaning:

Start Test 2, inhibit dropping unit
and loop on error.

Software Parameters - Refer to Diagnostic Listings.
VAX-Based Remote Diagnostic
VAX Front-End Diagnostics (EVMBD, EVMBE) - These two tests check the subsystem in all basic
modes of operation, and test the TU80 logic, interface bus and I/O silo. These tests can be run with the
host off-line only.
VAX Data Reliability Diagnostic (EVMAA) - This check is designed to thoroughly check out the tape
subsystem. It allows the operator to test the TU80 on-line without bringing the system down. The diagnostic consists of the Qualification Test and the Data Reliability Test.
Data Reliability Test Sections
Test I : Qualification Test 1
Test 2 : Qualification Test 2
Test 3 : Data Reliability Test
Test 4 : Multi-Drive Test
Test 5 : Conversation Mode Test
Test 6 : Streaming Test
NOTE
Test 1 is not run on TU80.

6-24

Operating Instructions for VAX-Based Diagnostics
Follow this procedure when using VAX-based diagnostics.
1.

Load the Diagnostic Supervisor (ECSAA, ENSAA, or ESSAA).
NOTE
ECSAA is used on VAX 111750.
ESSAA is used on VAX 111780.
ENSAA is used on VAX 111730.

Attach and select a device to be loaded in one of two ways.
a.

Prompt mode
DS> Attach DW7XX HUB DWO
Device Type? TU80
Device Link? DWO
Device Name? MSAO
CSR? 772520*
Vector? 224
BR?5

Explicit mode
DS> Attach TU80DWOMSA07725202245
DS> Select TU80

Load and start the diagnostic in one of two ways.
a.

Example 1
DS> Load EVMAA (or EVMBD, EVMBE)
DS> Start/Switches

Example 2
DS> Run EVMAA (or EVMBD, EVMBE)/Switches
No hard errors are allowed.
NOTE
For control flags, refer to the Diagnostic Listings.

* Base address (TU80's starting address is 772522).

6-25

EDUCATIONAL SERVICES - TRAINING PROGRAMS
Digital Equipment Corporation's Educational Services Group provides one of the most extensive educational
programs offered by a computer manufacturer.
Educational Services designs, develops, and delivers courses which help people learn skills and achieve
understanding and expertise in using computers. Our courses range from introductory to advanced, covering
basic computer knowledge through the highest level technical subjects. We design many courses for users
of Digital's hardware and software, and also create courses which are not product specific.
More than 500 courses, taught in 17 languages are available. Educational Services constantly creates new
courses which reflect the latest technologies, such as interactive video. Currently, the following training is:
Self- Paced Instruction (SPI)
Computer- Based Instruction (CBI)
Lecture/Lab Courses
Customized Courses
Seminars
Digital Press
Every quarter Educational Services publishes The Digest, a planning tool for developing individual training
programs. The Digest includes a complete list of available courses and their locations.
Please call your nearest Sales Representative or Digital Education Center for more information about the
courses and services you need; or contact
United States:

Customer Training Manager
Digital Equipment Corporation
Educational Services
12 Crosby Drive
Bedford, Massachusetts 01 730
Telephone: (617) 276-4373

Europe:

Customer Training Manager
European Area Headquarters
Digital Equipment Corporation International
12 Avenue des Morgines
Case Postale 510
CH-1213 Petit-Iancy 1
Geneva, Switzerland
Telephone: [41 ]-(22)-933311

Other Areas:

Customer Training Manager
General International Area Office
Digital Equipment Corporation
100 Nagog Park
Acton, Massachusetts 01720
Telephone: (617) 264-6783

Digital Equipment Corporation. Maynard, MA 01754