21 Aug
2002
21 Aug
'02
8:40 p.m.
Further clarification, and I can answer my own first question... see
below, please.
At 10:19 PM 8/21/02 -0700, you wrote:
I'm reverse engineering the PC boards in my Wang
2200. I have been able
to find most of the chips that have been used on the board I'm currently
workign on, except for a couple.
Does anybody know the pinout for these?
1) 8T10, quad latch (with either tristate or open-collector outputs, I
don't know which)
It is a TTL device, made by Signetics, I think. 16 pins. 1976 date
code.
(N8T10B is the fullly qualified part name
It turns out that the 74173 is the same part with a different name.
2) This one is a reverse job. The microcode board has
quite a few mask
ROM chips. I don't care what the actual part number is, but I'm hoping
someone will say, "hey, that pinout is just like a ..." so that I can find
a prom programmer to read the thing. If I have to, I guess I could build
a parallel port dongle to read them. Here's what I know:
24 pins
data out on pins 16-23
pin 1 is +5V
pins 2-8, 10, 11, 13, 15 are the address pins
pin 14 is either a chip select or output enable; active low
pins 12 and 24 are pulled up to +5; chip selects maybe?
pin 9 might be -15V (!)
One more thing, the manufacturer's logo and part prefix are "EA".
Thanks again.
-----
Jim Battle == frustum(a)pacbell.net