M710

This document is a proprietary schematic diagram for the Digital Equipment Corporation's PUNCH.CONTROL M710 module, copyrighted in 1970 and intended solely for test and maintenance purposes.

The schematic details a digital control circuit built primarily with DTL/TTL logic, utilizing various integrated circuits such as:

• NAND gates (DEC7400, DEC7401, DEC7430, DEC7440)
• Hex inverters (DEC7404)
• D-type flip-flops (DEC7474)
• Monostable multivibrators (DEC9601) It also incorporates discrete transistors (DEC65340), diodes (D664), resistors, and capacitors.

The circuit manages the operation of a punch mechanism, receiving various inputs including a "FEED SW" (feed switch), "SYNC BIAS", "SYNC PUN" (synchronization punch), "INITIALIZE" signal, and multiple I/O Processor signals (IOP1, IOP2, IOP4, M84-M88). It generates a range of outputs such as "PUN ACT" (punch actuate), "PUN DONE" (punch done), "SYNC PUN O" (synchronization punch out), "FEED" control, "CLEAR" signal, I/O status signals ("I/O IN INT", "I/O IN SKIP"), and an 8-bit output bus (PB0-PB7).

Key to its function are integrated timing and delay circuits, evident by components producing specific delays (e.g., 4.5ms, 5 seconds, 0.4/3 seconds), and utilizing "CLOCK A" and "CLOCK B" inputs for synchronization. The circuit operates on a +5V power supply.