Quickest way is to stick them in a computer to see what size they are.

If they have stickers on them, you can pretty easily tell what they are if you do a little bit of research.

And if you really want to do research, you can look up the chips themselves.

cyclone3d wrote:

Quickest way is to stick them in a computer to see what size they are.

If they have stickers on them, you can pretty easily tell what they are if you do a little bit of research.

And if you really want to do research, you can look up the chips themselves.

Is there any possibility of damaging the computer? If somethings physically damaged/shorted could it ruin the memory controller/etc? Also I don't have a working MB with 30 pin slots.

I made this 100x times and never damaged anything. For the 30 pin you usually need 4 of the same kind. If you have 3x1mb and 1x4mb it will display 4 mb ... not 7. So for your test setup install the largest simms you have and exchange only one to test.

Predator99 wrote:

I made this 100x times and never damaged anything. For the 30 pin you usually need 4 of the same kind. If you have 3x1mb and 1x4mb it will display 4 mb ... not 7. So for your test setup install the largest simms you have and exchange only one to test.

Almost none of them have labels identifying size. Might be that they are cheap junk ones to begin with and not worth my time.

Even if there isn't a label on it there are usually markings on the individual IC's and you can usually google the part number and datasheets will come up and have a description for the IC as something to the effect of 1Mx 1 bit DRAM or 1Mx 4 bit DRAM, on 30-pin simms the first part 1M tells you that the SIMMS are 1mb, the second part tells you how wide the data bus of the ram chip is so the data bus of all the chips will add up to 8-bit for non-parity ram and 9-bits for parity ram, so a parity simm that uses all 1-bit wide memory chips will have 8 chips on a non-parity simm and 9-chips on a parity simm, non-parity simms that use 4-bit wide chips will have 2-chips, and parity simms that use 4 bit wide chips are a bit strange since they will have 3 chips on them 2x 4-bit wide chips and one 1-bit wide chip

EDIT:This is for 30pin Simms only, although a similar concept applies to 72-pin simms, 72-pin simms will have a 32-bit bus for non-parity and 36-bit for parity, although on a 72bit SIMM you need to multiply the size of the ICs by 4 for a single sided 72-pin simm and by 8 for a double sided simm, for example if you find that the IC on your single sided 72-pin simm is 4M x 4 it means it is a 16MB module, and if you have a double sided module with 8M x 16 ICs it means it is a 64MB module

I was thinking about getting those stand alone SIMM testers years ago but they were pricey even then. Just sticking them into a motherboard and having the system recognize them does not mean they will work 100%. I still use memtest in DOS to check modules (especially new ones direct from China).

Anybody have a good cheat sheet on chip makings for density and layout?

Predator99 wrote:

I made this 100x times and never damaged anything. For the 30 pin you usually need 4 of the same kind. If you have 3x1mb and 1x4mb it will display 4 mb ... not 7. So for your test setup install the largest simms you have and exchange only one to test.

386SX and 486SLC have the "edge" here because they work with only 2 modules. Even better, a GUS PnP can identify a single 9-bit module but I'm not sure if Gravis' setup.exe can test it properly. On the other hand once you have 4 of the same batch an early 486 (that has 30-pin SIMM slots) can definitely run the tests faster than a 386SX with its 16-bit bus.

For 32/36-bit modules 486s have the advantage of running with a single module (having a 32-bit bus instead of the 64-bit Pentium bus) but they have low FSBs so a Pentium based system can test a pair of modules quicker and more thoroughly (ie. at a higher clock frequency).

alvaro84 wrote:

Predator99 wrote:

I made this 100x times and never damaged anything. For the 30 pin you usually need 4 of the same kind. If you have 3x1mb and 1x4mb it will display 4 mb ... not 7. So for your test setup install the largest simms you have and exchange only one to test.

386SX and 486SLC have the "edge" here because they work with only 2 modules. Even better, a GUS PnP can identify a single 9-bit module but I'm not sure if Gravis' setup.exe can test it properly. On the other hand once you have 4 of the same batch an early 486 (that has 30-pin SIMM slots) can definitely run the tests faster than a 386SX with its 16-bit bus.

For 32/36-bit modules 486s have the advantage of running with a single module (having a 32-bit bus instead of the 64-bit Pentium bus) but they have low FSBs so a Pentium based system can test a pair of modules quicker and more thoroughly (ie. at a higher clock frequency).

to add to that, 486 boards tend to have problems with EDO memory and only late boards tend to support it properly. If a 72 pin module doesn't run on a 486 it is still worth testing on a pentium machine (in pairs, of course).

i486_inside wrote:

Even if there isn't a label on it there are usually markings on the individual IC's and you can usually google the part number and datasheets will come up and have a description for the IC as something to the effect of 1Mx 1 bit DRAM or 1Mx 4 bit DRAM, on 30-pin simms the first part 1M tells you that the SIMMS are 1mb, the second part tells you how wide the data bus of the ram chip is so the data bus of all the chips will add up to 8-bit for non-parity ram and 9-bits for parity ram, so a parity simm that uses all 1-bit wide memory chips will have 8 chips on a non-parity simm and 9-chips on a parity simm, non-parity simms that use 4-bit wide chips will have 2-chips, and parity simms that use 4 bit wide chips are a bit strange since they will have 3 chips on them 2x 4-bit wide chips and one 1-bit wide chip

EDIT:This is for 30pin Simms only, although a similar concept applies to 72-pin simms, 72-pin simms will have a 32-bit bus for non-parity and 36-bit for parity, although on a 72bit SIMM you need to multiply the size of the ICs by 4 for a single sided 72-pin simm and by 8 for a double sided simm, for example if you find that the IC on your single sided 72-pin simm is 4M x 4 it means it is a 16MB module, and if you have a double sided module with 8M x 16 ICs it means it is a 64MB module

For a few moments I was thinking "When did I write this? 🤣!" till I figured out the obvious 🤣

i486_inside wrote:

Even if there isn't a label on it there are usually markings on the individual IC's and you can usually google the part number and datasheets will come up and have a description for the IC as something to the effect of 1Mx 1 bit DRAM or 1Mx 4 bit DRAM, on 30-pin simms the first part 1M tells you that the SIMMS are 1mb, the second part tells you how wide the data bus of the ram chip is so the data bus of all the chips will add up to 8-bit for non-parity ram and 9-bits for parity ram, so a parity simm that uses all 1-bit wide memory chips will have 8 chips on a non-parity simm and 9-chips on a parity simm, non-parity simms that use 4-bit wide chips will have 2-chips, and parity simms that use 4 bit wide chips are a bit strange since they will have 3 chips on them 2x 4-bit wide chips and one 1-bit wide chip

EDIT:This is for 30pin Simms only, although a similar concept applies to 72-pin simms, 72-pin simms will have a 32-bit bus for non-parity and 36-bit for parity, although on a 72bit SIMM you need to multiply the size of the ICs by 4 for a single sided 72-pin simm and by 8 for a double sided simm, for example if you find that the IC on your single sided 72-pin simm is 4M x 4 it means it is a 16MB module, and if you have a double sided module with 8M x 16 ICs it means it is a 64MB module

I know it's late, but thanks. Got a few weeks between semesters, so I think i'll tackle this pile of ram.

Labelmaker is your friend. Get a Brother one onsale (got mine for $9 @ OD) and buy the tapes off eBay ($5 shipped).

Run some memtest on them, and you can make them 'T' for tested or something. E.g. '4MB FPM - T'

dexvx wrote:

Labelmaker is your friend. Get a Brother one onsale (got mine for $9 @ OD) and buy the tapes off eBay ($5 shipped).

Run some memtest on them, and you can make them 'T' for tested or something. E.g. '4MB FPM - T'

That's if I can get any 4MB modules. So far looks like all 1Mb for the 30-pins. I'm really disappointed because I wanted to put at least 8MB in my SB32