Old ram identification
Posted by Expensive_Mail7739@reddit | vintagecomputing | View on Reddit | 17 comments
A few weeks ago I found a small box of miscellaneous old ram. I was able to figure out what most of them were, but I couldn't find anything about these ones. The only codes i could find was "K0-13N" on the back of them. Does anyone know what device they came from? The only thing I'm finding are people selling them on ebay.
funkympc@reddit
It looks like they fairly standard 30 pin simms. Super common for 386 and some 486 mobos. Although most 486 mobos used 72pin simms. Alot of other 90s computers/special purpose devices used 30 pin simms. I have a rack of vintage samplers that use them for example. They were also used in some of the routers of the era(Motorola Star comes to mind).
Weird_Childhood8585@reddit
I count 32 pins on these
H0verb0vver@reddit
It's 30.
Baselet@reddit
The ones rhat say 30 seem to have 30 and the ones that say 32 seem to have 32. Did you zoom in?
cybah@reddit
Older Mac’s uses then also
Der_Unbequeme@reddit
1MB 30pin Sim, SD-RAM with parity , 70ns.
For use in 286 (max 2), 386 & 486 machines.
MWink64@reddit
Why only 2?
Der_Unbequeme@reddit
most 286er boards can only address 2048MB RAM
MWink64@reddit
2048MB (2GB) in a 286 would be quite a sight to behold.
Assuming you meant 2048KB, I guess mine must be an exception, since I have 4MB (4 x 1MB) in it now.
Zentralschaden@reddit
I wanted to say it is 4x1mb 30-pin ram but why do 2 of them have 32 pins? I never seen that 😃
YogurtclosetOwn5322@reddit
Some niche 32-pin modules existed to circumvent specific designs or patents, the industry standard 30-pin SIMM was ubiquitous from the late 80s to early 90s, commonly found in 1MB or 4MB capacities. I remember having 32-pin SIMMs but they all fit the same.
Newsmaker_Goodcorp@reddit
Looks like those 2 pins are for Presence Detect (PD) function, which was used to encode the capacity and speed of the SIMM
Leftover_tech@reddit
There are 30 defined contacts per module, but some manufacturers placed an additional pad on each side. I think there was some idea about making the module more stable in the mounting space.
mega_ste@reddit
ooh, good spot, i've just grabbed a handful from my stash and they are all 30 pins
GGigabiteM@reddit
Those are 1 Mbyte parity modules of the fast page mode variety, rated at 70 ns.
The two chips on the left make up the 1 Mbyte and the one on the right makes up the parity bits.
justeUnMec@reddit
I was going to say standard 1m 30 pins sims but then I notice two of them are actually 32 pin, and 9 bit (8 bit + a parity chip) which is interesting.
mega_ste@reddit
they look like 1meg SIMMs. I have loads that I use to upgrade Atari STe machines, but PCs from the same era used them too.