Dec boards- what are they?

[Tom Peters]

I figured out what most of my stray DEC boards are-- DLV11 and such. These 
two baffle me. One might not even be a Q-Bus board like the rest.

Mystery board #1:

Pull-tab numbers: M7721 (Magenta)
Size: Small! regular 5-3/16 inches (132mm) width, but only 5 inches deep, 
including the fingers, not including the pull tabs.
Contents: 4 transistor, some caps, resistors, small glass diodes, 14 ICs 
which all look to be 7400 series TTL-- counters, flip-flops, quad-NAND, etc
Terminator? For what? It's cut for Q-Bus, but it's short.

Mystery board #2:

Unpopulated (except for U8, the only 28 pin IC on board, a Motorola 
MC3242A) in other words, empty sockets. Most of the sockets are 14 or 16 
pin, except for one 8-pin. 16 of the 16 pin sockets are laid out in two 
neat rows, which makes me think of memory. There's voltage inverter or 
charge-pump type chip at U20.
Markings: Solder side: "Copyright 1978 by Heath Company"  "85-2195"   "100478"
Component side: "81-2195-3" and "ADDRESS SELECTION" next to 8 jumper pads.
Gotta be a Q-Bus memory card, right?




[Science] Never express yourself more clearly than you think. --Neils
Bohr (1885-1962)
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