> > 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.
>
> Until you get a machine built in 1974 :-). It's happened to me, it's
> mentioned in 'The Art of Electronics', and it's doubtless happened to
> others here.
Too right. And they don't half misbehave when you mistake the date code for
the logic function :-)
I've got a large boxful of TTL with 74 date codes. Trouble is, I *still* can't
tell which is which on one or two of them, just by looking.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Received on Mon Apr 06 1998 - 19:16:36 BST