View Full Version : Baby Blue (Xedex) card: what RAM chips does it use?

February 21st, 2017, 12:33 AM

I picked up a Baby Blue CP/M card by Xedex, sans RAM chips. So, I need to know the details of the chips it uses, so I can try and get it working. A high-resolution photo of the board, with RAM installed, would be a big help. I can find no such photo on the internet. I found a poor-quality photo taken by an eBay seller; my request to said seller for a high-res version was not fulfilled. :(

If you can help, please post a photo of your board here or send it to me by PM.


February 22nd, 2017, 04:57 AM
All I can find is that it has "64K of Dynamic RAM", How many ram sockets does it have? If it's 8 or 9 my money is on 4164 or 4264 chips, those would have been the bog standard DRAM chips of that time period. Now I could certainly be wrong, but they can be found so cheap these days, that barring finding a manual or high res photos, I would just buy some and give it a shot.

March 9th, 2017, 07:56 PM
Several people suggested 4164, so that's what I bought & inserted. Then I installed the card in my IBM 5160, aaaaand ... the software (all versions) fail to detect the z80 chip. D'oh! :(
Actually I'm not surprised: the board is in terrible shape, all scratched to hell; I think some traces are cut. The poor condition is why I was able to pick it up for a low price, but... I actually want to use it.
Is there someone here (preferably in the USA) with good experience diagnosing ISA board problems and repairing them via soldering, etc., who would like to have a go at it?

March 10th, 2017, 03:21 AM
IMO, it's not worth it.

For the cost of diagnosing/repairing this item (if it can even be done successfully) you can probably buy several working cards.

March 28th, 2017, 12:31 AM
I contacted the seller and he was kind enough to swap out the damaged card for one in better shape. I bought some 4164 chips @ 200NS, and installed them. Then placed the card in my IBM 5160 and ...

It works! :D

Cool. And what a curious card it is. This is going to be fun to play around with, when I find the time.
I already have my 5160 equipped to dual boot in either MS-DOS 5 or CP/M-86. Now it can run CP/M-80 software too!