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Date   : Mon, 28 Nov 2005 02:31:19 +0000
From   : Richard Gellman <splodge@...>
Subject: Re: ATPL Sideways expansion board problems

According to the BBC B circuit diagram I have handy, there is a line of 
links marked S34 to S38, which are "made" by default. If one is broken, 
it wouldn't hard-deactivate the associated chip. S34 is attached to the 
MOS chip, S25 to S38 to the four paged ROM sockets.

Try looking for these links on the board... they may appear either as a 
loop of wire on the board, or as a track between two close pads - rather 
than the traditional two pin "jumper" arrangement. If these have been 
cut, you'll need to rejoin them (soldering required). If you're lucky, 
they will be the pin type, and you'll just need to put a jumper cap on 
them to re-activate.

-- RIchard

A. J. Davis wrote:

> Posting this on behalf of a friend:
>
> "I have a BBC Model B fitted with an Advanced Technology Products Ltd 
> (ATPL) Rom/Ram Sidewise expansion board. It works fine, except that 
> the four Rom sockets on the motherboard are inactive. In all the other 
> Model Bs fitted with ATPL boards that I have seen, these sockets are 
> active. Is there some way of inactivating the four sockets on the 
> motherboard - by changing a link for example?"
>
> Any ideas chaps?
>
> Thanks
>
> Andy.
>
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