6 Oct
2009
6 Oct
'09
2:46 p.m.
On 10/6/09, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
If you wish. I can check, too. It would be specifically for
repairing a DEC M220 register module for a PDP-8 of the era, so not a
general case there, either.
I think I just ran across a couple of those earlier this year. I'll
have to go see what's in my cabinets. I'm not especially worried
about the 7482s in particular going bad, but I do have more than one
CPU that uses M220 modules, and I'd feel better if I could replace any
component on that board without having to scramble (and pay too much
in shipping, etc).
I'll have to go check the printset, but it wouldn't surprise me that
the 7482 is also used in the PDP-11/20. Whatever adder chip is used
there, I should have a few of _those_ on hand, too (that machine is
one of my next restoration projects).
-ethan
Since I have a
small number of 74LS83s in my parts bins...
I can't remember if it will _always_ replace a '82 (there may be enable
pins that I've forgotten or something). I can check if you like. I think
I've seen 74LS83s for sale somewhat recently (at Unicorn or
some similar place).
The '283 is much the same device with a saner pinout (power pins in the
corners), so you could probably use that too