M220B (PDP-8/I) schematics available

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Thu Jul 17 18:36:19 2003

> > going. Oh, and a 7482 adder, which was impossible to find [1]...

[...]

> > [1] I do mean _iompossible_. I ended up using part of a 7483 that I stuck
> > to the flip-chip PCB dead-bug style and wired to the holes where the 7482
> > should have been. Runs fine...
>
> Bzzt. Wrong. (First, you probably mean "_impossible_" :-)).
> I just bought 5 of them for US$1.25 (or so) each from
> Gateway Electronics. Along with spare 7453, 7460, 7440, etc. I think it's
> something like "gatewayelex.com".

Notice I said 'was impossible to find'. At the time I was repairing this,
some 10 years ago (Eeek!), no UK supplier could supply them (and I
tried...). This was before the Internet was commonly available in the UK,
and we didn't really know the US suppliers of old chips.

-tony
Received on Thu Jul 17 2003 - 18:36:19 BST