M220B (PDP-8/I) schematics available

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Thu Jul 10 17:16:00 2003

[7482 chip]
> > [1] I do mean _impossible_. 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...
>
> You know what happens when someone says impossible...

'Somebody these days claiming something is impossible is apt to be
interrupted by some fool doing it' :-)

>
> I just checked my parts bins, and I have *one* 7482, a TI part with a date
> code of 7541. If you still want to replace your 7483 kludge, and know of
> an economical way to get small things from the US to the UK, let me know.

Actually, I got some 7482s a couple of years later. But I never bothered
to replace the kludge -- it works well, so I don't see any reason to pull
the card again. If it fails, I'll try one of the 7482s I have...

> Btw, what was the vintage of the old chip? Chances are one of the local

Around 1972, when the controller was made.

-tony
Received on Thu Jul 10 2003 - 17:16:00 BST