Spare Chips

From: William Donzelli <william_at_ans.net>
Date: Thu May 22 10:27:46 1997

> I have found what seems to be a decent supply of eproms. I was looking at
> an old 2400 baud fax modem for my pc, and noticed that it had what looked
> like an eprom on it. I pulled the chip and peeled off the label, and it was
> a 27256 eprom. I also bought a 2400 baud modem at a thrift store for $2.00
> and it had a 27128 eprom in it. This was cheaper than buying the eprom by
> itself. I paid $3.00 for a 2764, and didn't even price a 27128. I am going
> to start picking up all of the old cheap, almost worthless modems and
> grabbing the eproms out of them. You can probably pick up the modem for
> less than the price of the eprom that it holds. If anyone else knows of a
> cheap source of eproms or other chips, share it with us.

Hamfests are the best place to pick up spare chips. Many vendors are
simply regular guys just trying to clean out their basements, others are
psuedo-commercial vendors. Of course, it is just a big crap shoot - some
fests have yeilded only boards with standard TTL/CMOS, other fests have
yeilded more exotic species ($2000 1M Rad-Hard EEPROMS (buck a tube!),
GaAs glue logic, early weird 68000 variants, etc.). Of course, the
chances of finding exactly what you need on the first try is, by Murphy's
Law, slim (it does, however, justify going to every hamfest possible!).

I must caution that we must be careful what we scrap - for example, I am
pretty sure I scrapped out a bunch of CA Naked Mini (sound familiar?)
boards three years back. Many boards to classic minicomputers are not
distinctive at all (Data General leaps to mind), but are in demand. They
same holds true for peripherals.

I think we should use this list when we need parts. Some of us
probably have mountains of chips (at least I do). If you need a specific
chip, post something to the list - perhaps one of us has a tube of the
things we never knew we needed. I do not think anyone here is out to make
money on such small deals.

Regarding EPROMS and PALs: I would stock up on them, as both are becoming
obsolete. Flash technology has nearly wiped out EPROM demand, just as GALs
and FPGAs are pushing out PALs. And if you see ANY early or wierd EPROMs,
namely 1702s and 2532s, GET THEM. Today they are quite rare, tommorrow
they will be gone.

William Donzelli
william_at_ans.net
Received on Thu May 22 1997 - 10:27:46 BST