M105

This document is a proprietary schematic diagram for the Digital Equipment Corporation (DEC) "Address Selector M105" module, copyrighted in 1969 and intended for test and maintenance purposes.

The schematic details a complex digital logic circuit primarily composed of various integrated circuit (IC) logic gates (identified by specific DEC part numbers like DEC380, DEC8242, DEC8815, DEC74H00, DEC7402, and DEC8881), along with resistors, capacitors, and designated jumpers.

The circuit processes numerous inputs, including:

• Address bus lines (e.g., BUS A00 L through BUS A17 L, BUS C0 L, BUS C1 L).
• Control signals (SELECT 0H, 2H, 4H, 6H).
• Other inputs like BUS SSYN L, EXT CAP BI, and IN H. It generates two main outputs: OUT LOW H and OUT HIGH H.

Supplementary information includes component specifications (resistor values, capacitor values, IC types) and pin assignments for power (+5V) and ground (GND) for the different integrated circuits.