S-100 Polymorphic Systems card questions
I have a S-100 based system that seems to mostly run, but I have some
questions on the video card.
It is a Polymorphic Systems card, but looks different from all the examples I
could find on the internet
Markings are: Polymorphic Systems (c) 1976 I.P.C VIDEO? rev 0.0, with most
chips aligned vertically
The keyboard? port is a 14 pin DIP socket in the upper R.H. corner, next to a
8212 I/O chip.
Between this and the VIDEO marking, there are some pads with heat damage that
have the symbol for Zener diode across one of them. I have no idea what the
component specs are for these pads.
Also, 2 questions: does anyone have the DIP switch settings table for this
card? 7 switches, currently set at 1 1 1 1 0 0 0
and (2) the 8212 interface makes me think that the keyboard is some sort of
parallel interface, but the computer came with a DIP header connected to 3
wires
(bonus question: this card has some jumper wires and a resistor soldered on
the trace side of the PCB, is this official, or is this a hack? the joints look
sort of "hacky" the resistor goes between +Vcc and pin 20 of the 6571AL, the
jumpers are between some of the 74XXX gates on the L.H. side of the card
[where the 7805 V.R. is])
found it at my church garage sale several years ago, so I can't "ask the
owner"
Scott Quinn
Received on Mon Dec 27 2004 - 12:38:57 GMT
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