RC2015/01 project – PSE Pacer 16-bit microcomputer from 1976

One of the first available 16-bit microcomputers was the PSE Pacer, introduced in 1976.  (NOT the contemporaneous AMC Pacer, though I knew someone who had one).  My Retrochallenge project is to restore and reverse-engineer the Pacer, and time permitting, write some programs for it and/or build a higher-capacity memory board.

Project Support Engineering of Sunnyvale California sold the PACER in either kit or assembled form. It was one of the first 16-bit microcomputers, based on the National Semiconductor PACE 16-bit microprocessor. The PACER offered a calculator-style hexadecimal keyboard, and two four-character LED displays.

The entry-level PACER has:

  • unregulated linear power supply
  • motherboard supporting up to 11 card slots, with only 3 edge connectors installed (but note that the power supply is not beefy enough to support more than a few additional cards)
  • PACE CPU card
  • user memory card
    • 256 16-bit words (512 bytes) of static RAM, using four 2112 NMOS 256×4 static RAM chips
    • optional expansion to 1024 16-bit words of static RAM
    • optional expansion to
  • front panel interface card with monitor firmware (2048 16-bit words of ROM) and 256 16-bit words of monitor scratchpad RAM
  • front panel board with keyboard encoder and LED display drivers

There were several optional PACER boards, including a teletype interface.

There is a brief review of the PACER in National Semiconductor’s Compute Volume 2 Number 8.

I received the PACER without any documentation, and searches have turned up no documentation, hence my need to do some reverse-engineering.

I will put photos of the PACER in a flickr album.

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