Date   : Tue, 13 Sep 2005 16:31:48 +0100
From   : Rob <robert@...>
Subject: 2nd processor fault finding

Hi All,

OK I was lucky enough to pick up a 6502 second processor off ebay.  It came 
as a board only; no PSU or cables.

My problem is I can;t get it to work... I've made a ribbon by cutting down 
an old 40 conductor IDE cable, but when the board is connected to the beeb, 
it locks up.. (specifically, a B presents no display and a constant beeb, 
and a Master boots up fine, but locks up with no keyboard input accepted.)

I've tried it with the 2P powered on and off.  I've even swapped the tube 
ULA and swapped it with the one on a Master internal 6502, and it worked in 
there.  The odd thing is I get the same symptoms with the tube ULA removed 
from the board, when my reading of the circuit diagram indicates that 
nothing on the ribbon connects anywhere else!  The ribbon alone connected 
to a beeb doesn't affect it at all, which I would have thought it would if 
it were a problem with the cable.  I'm presuming I only need a straight 
through cable..?

Any clues anybody, or shall I get back onto the seller - he did advertise 
it as working.

Rob.