Re: Re: RE: 8096 repair

Hi,
 
Thanks a lot for all those answers - My MB is a revision 8032090 with UA17/UA19 socketed. I've tryed "just to see" to swap and to simply remove 4116 at those position. With no RAM on UA17 or UA19, it won't even emit any beep ... I'll try to find out some 4116 in my stock ! Would a 4164 make the thing ? Another question I'm asking me is where is "low" memory ? Is it UA4 to UA11 or above UA11 ?
I've tryed the floppy drive test - without success - it was a good try !
My plan would be 
 1) RAM - Swap 16Kb low/hi  (don't know if a quick hack is possible) to try to isolate or change the problem
 2) Bad solder .... as something had changed once (and I had something readable on display) when I pulled out UD12 from it's skcket.
 3) Try to be more intelligent.
Bad news, my "ancestral" Schlumberger CRC 5212 osciloscope died after half an hour of usage following 15 years of storage ==> Must find something to replace it.

Envoyé depuis SFR Mail. 10 Go de stockage - en savoir plus.


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Message du : 13/01/2011
De : "William Levak " <wlevak@SDF.LONESTAR.ORG>
A : cbm-hackers@musoftware.de
Copie à : ruud.baltissen@apg.nl
Sujet : Re: RE: 8096 repair



On Wed, 12 Jan 2011, hwarin@neuf.fr wrote:

> I feal this as a RAM problem - Is there any simple hack to limit memory to
only 16K or to easilly check RAM ?

It's not necessary. If upper memory is bad, the system will set the top of 
memory lower and still run. If it's low memory, the system will not run. 
It needs the first K of memory.

This could also be a bad ROM, or one of the address logic chips.

If upper RAM is good and only the lower RAM is bad, it should be possible 
to jumper the bank select lines to use the upper RAM instead of the lower 
RAM. The details depend on which version of the system board you have.

It could also be bad video RAM. Maybe the system is running and the bad 
video RAM is keeping you from seeing it. Try connecting a disk drive and 
typing some commands and see if the drive responds.

wlevak@sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org

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