[vcf-midatlantic] FS: Two Processor Tech 4KRA 4K Static RAM S-100 Boards Tested/Working

systems_glitch systems.glitch at gmail.com
Sun Oct 8 16:49:12 EDT 2017

Board #1: http://www.ebay.com/itm/272879702807
Board #2: http://www.ebay.com/itm/272879706168

I'm guessing both of these boards were used in the previous owner's Altair
8800 until they had RAM failures, and were likely replaced with something
newer and less power-hungry. These are one of Processor Tech's earlier
S-100 boards, and they use 32x low-power (for the time!) 2102 static RAMs.
Both boards have been repaired and fully tested in my IMSAI 8080 with a 2
MHz 8080 CPU board. The first one is fully socketed and had five dead
SRAMs. The second is not socketed and had one dead SRAM, which was replaced
with a machine pin socket. The second one used soldered jumpers for address
selection, so I switched it over to machine pin sockets for easy

I'd suggest that these boards not be purchased by someone wanting a static
RAM board for general debugging -- they're low-density, I don't believe
they support the *PHANTOM line, 2102s aren't the world's most reliable
SRAM, etc. They'd go nicely with an original Altair 8800 (especially if you
have a CUTS system!) or SOL-20.


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