chip pinout help

From: Jim Battle <frustum_at_pacbell.net>
Date: Thu Aug 22 00:40:01 2002

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_at_pacbell.net
Received on Thu Aug 22 2002 - 00:40:01 BST