Manufacturer: Hewlett Packard (HP)Part Number: 07970-61080 (Series H-1042-42)System: HP 7970B / 7970C Digital Magnetic Tape UnitFunction: Main Control and Status Logic Board.Condition: Removed from a vintage HP 7970B system. This is a high-density logic board featuring a large number of vintage ICs and heavy gold-plated traces. Sold as-is.
Main ICs and Key Components
This board is packed with early 1970s digital logic. Most of these 1820-series HP parts cross-reference to the standard Texas Instruments SN7400-series TTL logic:
- HP 1820-0054 (U1, U4, U14, U16, U21): These are very common Quad 2-Input NAND Gates (equivalent to a standard 7400 IC).
- HP 1820-0256 (U6, U7, U8, U9): These are likely Dual J-K Flip-Flops or similar sequence logic (equivalent to the 7470 series), used to track the "state" of the tape drive.
- HP 1820-0348 (U12, U15, U18): Specialized logic (often equivalent to 74121 one-shots or decoders) used for timing the transport movements.
- HP 1820-0077 (U3, U17): Similar to your other boards, these are core logic gates used for signal buffering.
- Blue Multi-Pin Connector: A heavy-duty interface connector used to link this logic board to the rest of the mainframe.
Let me know if you are interested in any other parts from HP 7970B Digital Tape Unit.