Assembler Programming Under ETOS

This document provides technical programming information for assembly language on the ETOS system. It serves as a guide for developers working at the machine level using PDP-8 assemblers (such as PAL8, SABR, RALF, or MACREL) while operating under the OS/8 or COS environments.

Key sections of the document include:

• Introduction to Assembler Programming: Outlines the development environment and provides references for further study.
• Terminal and Memory IOTs: Details specific Input/Output Transfer (IOT) instructions for terminal handling, extended memory control, and time-sharing features.
• Card Reader and Line Printer IOTs: Describes instructions for interacting with card readers (including various modes like alphanumeric, binary, and compressed) and line printers.
• System Functions: Details extended system functions (SYSCAL) such as setting the switch register, obtaining the time of day, managing job sleep/wait states, and retrieving system information via the DATAPK function.
• File Management (Chapter 7): Explains ETOS channels, which are used to access files, and provides detailed documentation on Channel I/O commands (such as READ, WRITE, ENTER, LOOKUP, EXTEND, and REDUCE) available through the SCALE command language and assembly language programming.
• Error Messages: The document includes comprehensive appendices listing error messages generated by various system programs (OS/8 and COS), as well as character code tables for OS/8 and COS systems.