6 Oct
2005
6 Oct
'05
2:46 p.m.
Then you might
be abloe to identify some pins as definite inputs (driven
from totem-pole outputs on known ICs), others as definite outputs (only
go to known inputs).
If all else fails you may have to desoler the IC, power it up on a
breadboard, find outputs with a logic probe, try the inputs, and so on.
I used to have an article out of one of the electronics magazines that
told how to identify various pins on ICs using an ohm meter. Input pins,
output pins and power and ground pins all have different characteristics. Unfortunatly I lost the article. Does anyone have any
info on how to go
about doing this?
How about starting with a known IC of the family you're interested in and
recording the results for your meter between various combinations of the
pins?
But all in all I like Tony's Suggestion of looking for the parts with
dual markings and make a cross reference list. When you get done, post it
on the net to benefit everyone. Spere has a good start on HP and Tektronix
cross reference on their website.
I know for a fact that some of the IC's on that HP list were indetified
by finding dual-marked ones on HP boards. And others were indentified by
finding inputs and outputs and indentifying the functions. I know this,
because I did it :-)
There was a good HP equivalent list published _by HP_ in Bench Briefs at
one point. It was half a dozen pages, 3 columns, fairly small font. I
haev it, but I know it wouldn't stand scanning or copying, and I don't
feel like typing it all in.
-tony