--- Tony Duell <ard_at_p850ug1.demon.co.uk> wrote:
> I think I'd try to move the 'core mat' (cores + wires) from the parity
> plane to the data plane and then repair the defective one.
Not feasible. The X-Y wires run from one side of the PCB to the other and
intersect two bits at a time, 64 cores each. It's not like a PDP-11 board
(the only other one that I can look at right now).
> Yes, it's a lot easier just to swap sense wires round, but that seems like
> a kludge to me.
I suppose I can start with disassembling the mat that seems easiest to get
to, then decide on what to do with the parity bit from there.
> I guess it comes down to : Do you need to _use_ this machine (when
> swapping the sense wires round makes a lot of sense) or are you tryign to
> restore it (when you make as few mods as possible).
I have more than one PDP-8/L. I could always borrow a known good core stack
from an -8/L and stuff that in the -8/i. It's not as if our hobby depends
on the provenance of spares as a "genuine" antique would. It's virtually
impossible to guarantee that any particular part was *never* replaced over
the lifetime of the machine.
In order, I would like it to A) work, B) be aesthetic. A+B is optimal. A
alone is acceptable.
-ethan
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Received on Mon Apr 19 1999 - 21:24:03 BST