Re: 2001 repair help

From: Gerrit Heitsch <*gerrit_at_laosinh.s.bawue.de*> Date: Wed, 27 Dec 2017 20:29:26 +0100 Message-ID: <d1fe2293-c44b-3e1f-e603-ad5f88074431@laosinh.s.bawue.de> · gerrit_at_laosinh.s.bawue.de

On 12/27/2017 08:18 PM, vossi wrote:
> Normally at this boards the half of the 6550 and some 6540's are dead...
> Often the 6520 are faulty too.
> The sockets are a very big problem. Commodore used in the old 2001 the high
> black sockets with metal outside - these are very bad! Also they have not so
> high sockets with metal contacts inside - these are much better. And they
> used TI-sockets with very thin holes - these are the best!.
> 
> I have a rom-replacement board that fits in H2 to H5 as 6540 replacement.
> And I test the RAMs and ROMs with my 2001TEST in H7 (with adapter 27xxx to
> 6540). You find it here: http://lc64.blogspot.de/2016/10/

You write that the EPROMer is unable to read the 6540 since it needs a 
clock signal. Have you tried to use A0 from the EPROMer as the clock 
signal and just shift all other address signals by one? That will need 
some work on the resulting file, but you might be able to read a 6540 
that way.

  Gerrit

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