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Date: Sat,  2 Sep 89 05:19:40 EDT
From: "Robert E. Seastrom" <RS%AI.AI.MIT.EDU@MINTAKA.LCS.MIT.EDU>
Subject:  Desoldering tips
To: pdp8-lovers@MC.LCS.MIT.EDU
Message-ID: <640213.890902.RS@AI.AI.MIT.EDU>


I've got a dead 8/L that I've been meaning to work on for a while now.
The problem can be traced to 2 M220 boards (registers) that have stuck
bits or that the carry won't work on.  If I swap the boards with another
8/L, then everything is cool.  Now, I have tried to work on these boards,
but the extender that I have is flaky, and will break the machine even with
a good board in it.  I've decided that, since the total cost of all the
chips on an M220 is somewhere in the $6.00 range, the easiest solution
would be to just replace them all (yes, I know that shows no finesse, but...)
Anyway, I have replaced chips on the M220s before, and had problems with
the pads and traces coming off of the board.  So...  I solicit you folks'
help and any suggestions that you may have for getting the chips off
with the least pain and no damage to the board...

                 ---Rob


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Date: Mon,  4 Sep 89 16:31:09 -0400 (EDT)
From: Jaap Akkerhuis <jaap+@andrew.cmu.edu>
To: PDP8-LOVERS@mc.lcs.mit.edu
Subject: Re: Desoldering tips
In-Reply-To: <640213.890902.RS@AI.AI.MIT.EDU>
References: <640213.890902.RS@AI.AI.MIT.EDU>

> Excerpts from internet.pdp8-lovers: 2-Sep-89 Desoldering tips "Robert E.
> Seastrom"@MIN (881)

> So...  I solicit you folks'
> help and any suggestions that you may have for getting the chips off
> with the least pain and no damage to the board...

The easiest way is not to desolder the old chips at all.

Just cut the pins close to the chip housing, then solder the replacement
chips on these pins. Of course, you have to do this quickly. Also, you
might need to cut the pins on the new chips short to prevent the chips
to stick too much out depending on the space available between the
boards.

	jaap
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Return-Path: <BQT@KICKI.STACKEN.KTH.SE>
Date: 30-Sep-89 13:44:01 +0100
From: Johnny Billquist <BQT@kicki.stacken.kth.se>
To: pdp8-lovers@mc.lcs.mit.edu
Subject: FPP8A
Message-ID: <12530371065.30.1113.109380@KICKI.STACKEN.KTH.SE>

Is there anybody out there...

who has a FPP8A to sell, exchange for other hardware, or give away?

Also. Doesn't anybody write anything, or is it just that nothing
reaches me?

C'mon. How about discussing where to get hardware. Anybody got
a good place to lookup?

How about software? We really should put up a library somwhere.

Anybody with experience of the KT8 could enlight me on how it works.

I read a file describing a card used with ETOS, for more memory,
who also handled Data break, a real MMU actually.
Anybody seen one of these?

	Johnny
   --------