Speaking of Repairs - LS ADM31

From: Roger Merchberger <zmerch_at_30below.com>
Date: Mon Jul 17 19:18:19 2000

Sorry, Tony... but I thought "What the heck - I need a terminal for one of
my VAXen, and I have these two Lear Siegler ADM31's that have been
garage-bound for over a year... (rescued for $5.00 USD for both)

So I just "plugged 'em in" to see what would happen... [Well, not quite - I
at least popped 'em open, and reseated the socketted chips first...]

One seemed dead other than the caps-lock light would toggle as you pushed
that key (so there's hope), but on the other, the video seemed to work, and
I got several screenfuls of '8' and '0' [zero] and inverse-video '8' and
'0' [zero]... and there it sits.

Just a quick background on the box (from what I could view from the
inside... Firstly, its a damn computer in it's own right! It's Moto6800
driven, with 2 EPROMS (2716, IIRC) for the program & 1 EPROM for the 6845
character generator... a couple K of RAM (don't remember specifics) and
lotsa 7400 series TTL.

Does this sound like a normal failure mode of an ADM 31? (I have absolutely
no dox for the machine...) Could it be bit-rot on the EPROMs, or is this
normal startup if there's no serial cable hooked up to it? I have to make a
cable from my VAXen to the RS232... I want to make sure the terminal is
worth diddling with (read: easy enough to fix) else I'll just hook up the
[dusty] Pentium 100 and run a terminal proggie until I have more time
(read: in a few years)...

BTW, test equipment I have include a DVM/Freq counter & a 'scope, but
sorry, no logic tester...

Any help will be most welcome! TIA,
Roger "Merch" Merchberger

P.S. I'll give more info when I get home...
Roger "Merch" Merchberger   ---   sysadmin, Iceberg Computers
Recycling is good, right???  Ok, so I'll recycle an old .sig.
If at first you don't succeed, nuclear warhead
disarmament should *not* be your first career choice.
Received on Mon Jul 17 2000 - 19:18:19 BST

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