Hi! I recently obtained a "mystery" IBM PC board. It has a Z80 CPU, two
CTCs, 8K of SRAM, and a bunch of 74LS logic. I *suspect* this board is one
of those VCR backup boards from the early 1980's.
The only text on the board is described by its previous owner on
Vintage-Computer.com forums:
QUOTE
i don't think the EGA cards used a Z80bCPU chip or a 12mhz crystal...
i did find some numbers on the card...
Audio Visual Laboratories, Inc.
27122 R0I
M14A 94V0
Serial Number 1518
i know i looks like an EGA card, but it doesn't even try to initialize a
monitor on the rca jacks or the 9-pin port...
UNQUOTE
The ROM (AM27S29PC, 512x8 bipolar PROM) has a label that says "GENESIS
7-11-84"
I did some research on Audio Visual Laboratories and apparently they are
related to the old Eagle computer people. According to Wikipedia, Eagle had
a relationship with Corvus for hard drives and backup so I am thinking this
board *may* be a Corvus XT Mirror board relabeled by AVL. That is a guess
though.
http://n8vem-sbc.pbwiki.com/browse/#view=ViewFolder
<http://n8vem-sbc.pbwiki.com/browse/#view=ViewFolder¶m=AVL> ¶m=AVL
Does anyone recognize this board? Does anyone have software and/or
documentation for the Corvus IBM XT Mirror? I already checked
bitsavers.org
and Howard's archive. They mention the existence of an "IBM XT Mirror"
board but almost no other information on it.
Any help is much appreciated. Thanks in advance. Have a nice day!
Andrew Lynch