6 Oct
1999
6 Oct
'99
9:56 a.m.
I have an old multibus-1 board from "Little Machines" on which the 186's
and
'286's among other things are wired backwards and soldered to the board
because the original Intel data sheet didn't distinguish between the top and
bottom of the JEDEC "A" package which is a leadless ceramic chip carrier of
the type often seen in early PC/AT types. The board is so busy you can
barely see any of the surface, and it's much the same on what ought to be
the wiring side, as there are oodles of passives and other small-outline
parts, I'd say as many as 1000, on the "back" of the board, since there
wasn't room for anything more on the "front" where there are well over 100
DIP packages of various sizes.
This solder-in of the leadless chip carrier package was done interestingly
enough, in that the pins from an LCC socket were aparently extracted and
soldered, one-by-one, to the board and the device inserted UNDER them in
order to allow them to be soldered from the top.
It can happen to anyone, I guess.
Dick
-----Original Message-----
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Wednesday, October 06, 1999 1:14 PM
Subject: Re: Help wanted in dumping EPROMs
time...
Yes indeed! The data sheets for the two parts will answer all the
questions. All one has to do is to stay awake. I wouldn't make such a
statement if I didn't know of instances where one has gone to sleep . . .
that's one who shall remain nameless . . .
Make it 2, OK :-). I very nearly wired up a transputer socket
mirror-reflected because one book showed the chip from the top and
another showed the socket from the bottom. I caught the error just in
-tony