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View Full Version : PS/2 Model 30 286, anything funky about the RAM?



deathshadow
August 22nd, 2013, 08:00 PM
I just went through my entire stack of 30 pin RAM's, ranging from 70ns to 120ns, matching sets across the board, in both 8 and 9 pin flavors, and NONE of them seem to work as replacements for the 256k sticks the thing has in it. I know my 4 meg sticks won't work, but I'm surprised that I can't get ANY of the 1 meg sticks or even 256k sticks to work.

... side note, the first pair of 256k units in this rig are weird -- never seen massive RAM like that, much less opposing mounting directions. The other pair looks like normal cheap crap... memory types check out as normal ram for 256k chips... so I'm wondering why I'm having issues using anything other than the RAM it came with.

Stone
August 23rd, 2013, 03:03 AM
IIRC, you need IBM branded ram for this beast.

I have four 1 MB sticks if that's of interest. (1M X 8 -70)

nestor
August 23rd, 2013, 07:43 AM
Yes, those Model 30 SIMMs are not standard. You can modify standard 1 MB parity SIMMS to work in that system, but only SIMMs with 9 ICs will do (the 3 IC modified SIMMs hang the system randomly)

Al Hartman
August 23rd, 2013, 10:48 AM
Here is an old thread if it's helpful.

http://www.vintage-computer.com/vcforum/archive/index.php/t-20217.html

deathshadow
August 25th, 2013, 04:35 PM
Yes, those Model 30 SIMMs are not standard. You can modify standard 1 MB parity SIMMS to work in that system, but only SIMMs with 9 ICs will do (the 3 IC modified SIMMs hang the system randomly)

Know of anyplace that outlines doing that? I've got plenty of 30 pin memory to experiment with.

k2x4b524[
August 25th, 2013, 06:58 PM
would this also be why the PS/2 56SLC refuses to see more than 8 or 12 despite having 16 onboard?. I find it weird, but am also not surprised that IBM would do such a thing

nestor
August 25th, 2013, 11:39 PM
Know of anyplace that outlines doing that? I've got plenty of 30 pin memory to experiment with.

Follow this link: http://john.ccac.rwth-aachen.de:8000/misc/ps2cache/