​SSM IO-4 S100 I/O Interface Board 2-Serial 2-Parallel Altair IMSAI Untested For Sale

​SSM IO-4 S100 I/O Interface Board 2-Serial 2-Parallel Altair IMSAI Untested
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​SSM IO-4 S100 I/O Interface Board 2-Serial 2-Parallel Altair IMSAI Untested:
$119.99

Vintage 1977 Solid State Music (SSM) IO-4 S-100 I/O Board


Up for sale is a classic 1977 Solid State Music IO-4 Input/Output expansion board for S-100 bus microcomputer systems.


  • ​Features: Designed to provide two serial I/O ports and two parallel I/O ports. It features SMC COM8017 UART chips and the iconic blue SSM solder mask.

  • ​Condition: Cosmetically in good shape with clean gold-plated edge contacts. Due to the lack of a compatible test system, this board is completely untested and is being sold As-Is for parts, vintage computing restoration, or component harvesting. Please review all photos for exact condition and chip numbers.
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