20 Mar
2002
20 Mar
'02
6:18 a.m.
--- "James B. DiGriz" <jbdigriz(a)dragonsweb.org> wrote:
Ethan Dicks wrote:
> As for the TI 980B, with the exception of the
very scary, undocumented,
> rack-mounted 2-square-feet of prototyping board that was cabled into
> the DMA slot, it looks very clean. I have no idea what this peripheal
> was supposed to do.... it's covered in bent pins and broken wires...
> ...several missing chips
You've got me curious now. A comprehensive set of
shots are definitely
in order. I'm also getting a heavy vibe that you shouldn't go plundering
the board without determining what it does, who built it, and why,
first. Just a feeling that whoever built it may be wondering what became
of it and might be willing to underwrite a lot of component purchases in
order to reacquire it.
I have no solid knowledge of where this came from, but from the
construction
techniques, it's a prototype, not a custom-engineered one-off. The
connectors are sawed in half for the (original equipment) I/O card,
and the DMA connector cable adapter is a sawed-up extender card from a
different bus with stripped ribbon cable ends soldered to the traces
(several of which have seperated due to poor technique). I have at least
three components which have fallen out and several broken wires, making
a full schematic impossible. It might be able to document enough to deduce
what it does, but not precisely how it does it.
The 980 was used as a process controller, AFAIK. This is probably some
custom interface to some data collection equipment and perhaps some
actuators for use in the school electronics lab. I doubt this came out
of TI, given how it's put together.
It's always a possibility with a one-off or
prototype like this. Dunno
why I'm getting such a strong feeling in this case, but I am. Maybe I'm
wrong, but I wouldn't go stripping that board just yet, if it were me.
I'm not doing anything right away. In any case, I wouldn't pull (more)
chips without a map. The only reason why I'd consider stripping it is
because the chips are c. 1969-1975 and the perfect thing for fixing
PDP-8s, etc. 7474s, not 74LS74s (not that most stuff is critical,
but it's nice to have contemporary replacements). The guy who gave me
the 980 in the first place has no interest in any RTL chips he finds.
He wants to keep the TTL for his students, but I may try to buy him
tubes of modern chips and trade him for the older ones. We'll have to
see. He at least promised me the RTL.
-ethan
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