DEC 11/70...

From: Kevin McQuiggin <>
Date: Mon Apr 6 11:00:42 1998


Date codes are stamped on just about every IC, and some other parts too.

They are generally a four digit number of the form YYWW, where YY is the
last two digits of the year in which the chip was munfactured and WW the
week number, from 01 through 52.

Examples would be "7830" for the 30th week of 1978, and "8101" for the
first week of January 1981.

Generally for the old machines we talk about on this list, the chip type
code is easy to differentiate from the date code, because of the
prevalence of 7400-series TTL chips. Any 74xx or 54xx number will be the
chip type, while the other number will be the date code.

This helps to determine a general time frame for manufacture of the board,
at least you can tell generally within a small time frame when it was
manufactured, as big manufacturers like DEC didn't stockpile chips before
stuffing boards with them.

Hope this helps. If someone wants to snip this and add it to the FAQ then,
barring a more complete response, this would help other new users!


> On Mon, 6 Apr 1998, Tim Shoppa wrote:
> >
> > Can you at least look at some of the date codes on the chips? (Would
> > it be useful if I prepared a brief lesson on "how to read date codes"?
> > I have to admit that it's pretty obvious to me, and I often don't
> > understand how someone can look at a board and not just innately know
> > how old it is because of the date codes blatantly stamped on most
> > of the chips.)
> Things like that should be part of the faq.
> Aaron

Kevin McQuiggin VE7ZD
Received on Mon Apr 06 1998 - 11:00:42 BST

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