Next project: 11/24. Does it need memory?--Memory sad!

Jerry Weiss jsw at
Mon Oct 26 20:42:41 CDT 2020

On 10/26/20 8:31 PM, Chris Zach via cctalk wrote:
> Ok, so I'm now troubleshooting the memory parity errors in the MS11-L 
> memory. And yes, there are bit errors in the memory. I wrote a simple 
> program to check the first 64k bank and I've found errors in bit 2 but 
> not everywhere but on a predictable pattern of addresses. Interesting, 
> possible that one of the address drivers is shot in that particular 
> chip..
> Checking the board I can see that most of the chips are ITT chips, 21 
> 16935 01. However I can also see that this is not this board's first 
> rodeo, as several chips have been replaced with ITT chips 8411x 21 
> 14897 01 models.
> Is there an equiv model for these chips that can be found? Looks like 
> a 16k*1 16 pin MOS ram chip with +12,+5,and -5 voltages (wow!). I 
> guess if they can't be found I can pull chips from the parity section 
> and just ignore parity but I'd prefer not to desolder/resolder chips.
> As they say, it ain't gonna fix itself so I might as well get going on 
> it. ;-)
> CZ

I have used this site to help me determine substitutes for memory chips 


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