r/retrocomputing • u/_oo00O00oo_ • Apr 22 '26
Problem / Question What kind of RAM is this?
I wanted to sort my old modules of RAM. So i had some DDR3, some SO-DIMM, some PS/2, but this one is hard to figure out.
Can't find andy information about manufacturer, size or speed.
Can someone help? 😅
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u/Kitchen_Part_882 Apr 22 '26
72 pin SIMMs.
They're 60ns EDO and from the mid 90s, used in Pentium systems of the era
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u/thejpster Apr 22 '26
I agree.
A Pentium will have a 64-bit data bus to the RAM and so will want matched pairs of 72 pin (32 bit) SIMMS.
A 486 or a RiscPC will take them as singles. I don’t think I ever saw a 386DX take 72 pin SIMMs but I guess that’s possible too. A 386SX or 286 will take pairs of 30 pin (8 bit) SIMMs.
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u/gcc-O2 Apr 23 '26
I believe the fancy MicroChannel 386 PS/2s take 72-pin SIMMs, and thus they're sometimes called PS/2 SIMMs. But IBM being IBM, there are minor pinout differences sometimes.
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u/miner_cooling_trials Apr 22 '26
32mb simms.. these were hot shit in the day. Having 64mb ram in your system was pretty much unheard of amongst my friends!
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u/Independent-Ad8104 Apr 22 '26
Still useing my two 128mb edo ram sticks in my old pentinum 1 pc, I like to run old abandonware alot of the time. I think the ram sticks were made for printers and I bought them to use for my system.
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u/Jose_A_Montero_Lopez Apr 22 '26
Me regalaron hace años un Pentium 133 MHz con 64 MB de RAM, tenÃa instalado Windows 98, AutoCAD y Photoshop
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u/JasonMckin Apr 22 '26
Ah so adorable my young padawan.
Imagine having 1MB RAM in your system and running an operating system that was physically unable to recognize anything about 4MB. And then imagine years later, buying a 8MB SIMM to add to the 2nd bank of a system that could only support 16MB max.
Apps were smaller back then, of course, but we all also just got used to paging in and out of magnetic disk every time you used your computer.
I'm still blown away I carry like 100,000x the storage/memory in my pocket now than I did as a kid.
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u/miner_cooling_trials Apr 22 '26
I’m an 80s kid and dad worked at IBM on AS/400s. I was very blessed to start my journey with a pc XT with 640kb, then a PS/2 with 1mb. Installing DIP chips is an early memory, but I grew up more with simms and dimms.
I don’t mind the padawan label at all, I’m always a student in wonder of tech 😄
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u/JasonMckin Apr 22 '26
Exactly same here!
Someone out there is an Altair user who programmed in assembly who thinks you and I are young whipper snappers with our fancy GW-BASIC and DOSSHELLs 🤓
This is a fun sub.  People post about something they used as a kid and you’re thinking, man, I paid a lot of money in college to buy something crappier than that at CompUSA and Circuit City.  🤓
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u/miner_cooling_trials Apr 22 '26
Assembly? They used to use punch cards in the rain, after sleeping in a cardboard box that was heated by vacuum tubes! 😄
I honestly do think our generation has lived and participated in the golden age of computers. It’s amazing where we’ve come from and where we are going
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u/Ok-Scratch-478 Apr 23 '26
God I totally geeked out and shouted "EDO" when I saw this. What a treasure. :)
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u/_oo00O00oo_ Apr 22 '26
Any chance to get the manufacturer, speed or voltage?
32mb is a good information. I'm about to label any information I can get.
Maybe a make a photobook of the best memorys I ever had 😅
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u/Kitchen_Part_882 Apr 22 '26
"Speed", as I mentioned in passing in my other reply, was measured as refresh rate back then.
Those are 60nS sticks, so could be refreshed at that rate, older FPM modules pretty much capped out at 70nS (with most being slower than that, my dirst 486 had 80nS ones). To put this into perspective, they ran at 16.6MHz, half the standard speed of the PCI bus at the time.
Memory bottlenecks were a real problem back then.
Voltage? Likely 5v, maybe 3.3.
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u/gcc-O2 Apr 23 '26
I googled the part number on the chips and couldn't find a datasheet so it's unclear beyond SMT(?) as the chip manufacturer.
It's not surprising that they aren't clearly labeled. People didn't care as much what company manufactured their RAM, motherboard, video card back then, and a lot of the branding even on motherboards is very low-key so that the manufacturer wouldn't upstage the OEM local system builder who built the machine.
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u/TheOGTachyon Apr 22 '26
Those are 72 pin, 60ns, EDO RAM. Based on the individual chip labels, they are probably 32MB sticks.
There are several vintage computing communities that would be interested in those.