MP01385 DECSA Communications Server Engineering Drawings Vol2 Feb83

This document is a comprehensive Field Maintenance Print Set compiling detailed technical information for several distinct electronic systems. It serves as a complete maintenance guide, providing various levels of documentation to support troubleshooting, repair, and assembly.

The main systems covered in this set include:

1. MDECS-AA (256K x 22 MOS Memory System): Includes a block diagram, various timing diagrams (DATO, DATOB, DATI, REFRESH), and a flow diagram, alongside a general specification and an index of its associated prints.

2. DEUNA Module (Port and Link Modules): This is the most extensive section, featuring detailed drawing directories, circuit schematics (for various control registers, DMA engine, memory addressing, etc.), etch cut drawings (physical layouts), comprehensive parts lists, PAL (Programmable Array Logic) listings, and PROM (Programmable Read-Only Memory) pattern listings for firmware. It also contains numerous timing diagrams illustrating signal behavior for communication (e.g., UNIBUS, Ethernet Link), DMA operations, and state diagrams for complex logical sequences like receive/transmit state machines and collision back-off.

3. MS11-P Memory System: Provides its own dedicated field maintenance print set, including a block diagram, detailed timing diagrams (for various signals and operations), a flow diagram, parts lists, schematics for memory arrays, address/data control logic, CSR (Control/Status Register) functions, RAS/CAS (Row/Column Address Strobe) drivers, refresh logic, microsequencer, and power distribution. It also includes specific rework instructions for certain components and physical layout diagrams.

Beyond these core systems, the document also contains:

• Cable and Harness Assemblies: Detailed drawings and parts lists for various cables (e.g., Null Modem, V.35 Modem, I/O cables), bulkhead assemblies, and power harnesses, often specifying lengths and connector types.
• Fan Plate Assemblies: Drawings and parts lists for fan components essential for system cooling.

The entire document emphasizes its confidential and proprietary nature, restricting reproduction or use without written permission from Digital Equipment Corporation. It functions as a complete technical reference for qualified personnel involved in the maintenance and repair of the specified digital equipment.