On Mon, 7 Sep 1998, Alfred Arnold wrote:

> >It looks like the parity error is happening just below the 4MB boundary,
> >which would seem to indicate that it's a problem with memory card #1 (the
> >one in slot #5). Try removing that card and replacing it with the one
> >from
> >slot #3. You'll have to change a jumper on the card to mark it as RAM
> >CARD
> >#1 (or #0, depending on how they numbered those...). That will take you
> >down to 8MB of RAM, but it's probably your only solution if that mem card
> >is bad.
> 
> If it's really a 3/160, the first 4 Mbytes are on the CPU board and I
> don't know if there is a jumper on the board to disable the on-board
> RAM...so this might be a reason why the machine was thrown out :-(
> 

It is possible to replace the chips, I have a 3/140 which had a similar
problem (parity faults, lots of them at different addresses). Finding the 
dud chip was a bit of a problem , and its here I come clean with the 
nasty thisgs I did to my machine! To find the chip I cut the data-out pin 
of the 4116? 4164? memory chips in sequence to try to find a pattern as 
to address range /bit for each chip. I eventually found the right one and 
replaced it. Probably more by good luck than anything else. 

In this case I figured the machine was dead anyway and I coudn't make it 
worse. 

Of course if someone has details of how to map the parity fault details 
to a chip, its a piece of cake

			Ian (I love the smell of flux in the morning) Clark