From: dm561 at
torfree.net
To: cctalk at
classiccmp.org
Subject: Repairing core memories....
Date: Mon, 1 Nov 2010 11:54:47 -0500
Date: Sun, 31 Oct 2010 14:22:35 -0400 (EDT)
From: "O. Sharp" <ohh at panix.com>
Subject: Re: Repairing core memories....
On Sun, 31 Oct 2010, Jos Dreesen wrote:
So I have these 2 PDP-8/L core stacks I am trying
to recover:
One would be perfect, if bit 3 @ adr 0 would be alive...
Although this is 99.99% OK, it is of course not good enough.
<snip>
I suspect I'm not the only one on the list who:
-thinks opening up a core-stack and repairing it is
theoretically possible;
-also thinks it would be a hell of a daunting project;
-is somewhat amazed at the dexterity and patience of the people
who originally hand-wired them at manufacture; and
-thinks pulling off a repair of a core-plane by rewiring it by
hand would give significant bragging rights. :)
-O.-
+++++++++++++++++++++++++++
Agreed ;-)
But if anybody does want to, I've got a small (220x16) MDS (Fabri-Tek) core
plane with an already damaged section, cut-off edge connectors etc. to
practice on; for even more fun I could even throw in a few of two different
sizes of raw cores...
mike
Hi
One does have to match the cores. For this you have no choice but
to find a scrap core plane to get replacements from.
Each core, even though the same physical size, has a different
magnetic property. All the cores need to match. Having one
from the same manufacture and time span is about the
only way
to get the desired results.
Before I started reworking the core, I'd try swapping some
of the external wires to make sure the problem moved with the
core and not the address line drivers.
Dwight