Population of DEC M-8067 KA QBus DRAM board

[shirsch]

I have a couple of these for use in a QBus machine and noticed they are only 1/2 populated with (I assume) 64k x 1 DRAM chips. The current parts are labeled as Hitachi 21-18470-01. Has anyone successfully upgraded the boards by filling in the additional 4 rows (for an expanded total of 512k)? I'm hoping it's just a matter of adding an additional 32 chips along with 0.1ufd bypass caps.

 

[pbirkel@gmail.com]

Actually that's the HM4864P-2. Datasheets in the usual places.

 

[shirsch]

Actually that's the HM4864P-2. Datasheets in the usual places.

Thanks! Searching on 'Hitachi 21-18470-01' turned up precisely nothing of help. Still would like to know if this upgrade has a chance of working. Currently digging for information on jumper changes, schematics, etc. I have hundreds of HM4864-2 chips, so that's not an issue.

 

[pbirkel@gmail.com]

Probably, but first examine these two online documents regarding the "MSV11-P".

http://www.bitsavers.org/www.computer.museum.uq.edu.au/pdf/EK-MSV0P-UG-001%20MSV11-P%20User%20Guide.pdf

http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/dload/MP01239_MSV11-P.pdf

 

[shirsch]

Thanks for providing those links. It does appear to be as straightforward as I hoped. I'm not confident enough to solder the new chips, so the plan is to install sockets.