From that part code on the ZIP memory there, it appears to be an M5M41000 which is a 1mbit x1 memory chip.
https://www.datasheetarchive.com/datasheet/M5 … 1&term=m5m41000

There's 32 of them so you have a 32MB FPM SIMM there, pretty rare I think? They're using 32 to get it to the full 32-bits that the 72-pin SIMM uses.

That's a really cool module 😀

Thermalwrong wrote on Yesterday, 13:54:

From that part code on the ZIP memory there, it appears to be an M5M41000 which is a 1mbit x1 memory chip.
https://www.datasheetarchive.com/datasheet/M5 … 1&term=m5m41000

There's 32 of them so you have a 32MB FPM SIMM there, pretty rare I think? They're using 32 to get it to the full 32-bits that the 72-pin SIMM uses.

Cool

Thermalwrong wrote on Yesterday, 13:54:

From that part code on the ZIP memory there, it appears to be an M5M41000 which is a 1mbit x1 memory chip.
https://www.datasheetarchive.com/datasheet/M5 … 1&term=m5m41000

There's 32 of them so you have a 32MB FPM SIMM there, pretty rare I think? They're using 32 to get it to the full 32-bits that the 72-pin SIMM uses.

i can't find one to sell anywhere. it could have a expensive value. Which system could accept that ? my 486 vlb dont detect it, dont boot with it.

And another one... https://www-crashcomputer-com-br.translate.go … &_x_tr_pto=wapp

renejr902 wrote on Yesterday, 14:08:

Which system could accept that ? my 486 vlb dont detect it, dont boot with it.

A 486 system is supposed to work with a module like that. It should behave like a standard 4MB PS/2 SIMM, possibly slightly slower due to the extra buffering chips.

EDIT: Oops, does it say "-10" at the end of the model number of the ZIP chip? That would be a 100ns chips, which is too slow for 486 systems, at least at FSB33. You might try to lower the FSB to 20 or 25MHz to check whether the module is detected that way.

mkarcher wrote on Yesterday, 18:15:

renejr902 wrote on Yesterday, 14:08:

Which system could accept that ? my 486 vlb dont detect it, dont boot with it.

A 486 system is supposed to work with a module like that. It should behave like a standard 4MB PS/2 SIMM, possibly slightly slower due to the extra buffering chips.

EDIT: Oops, does it say "-10" at the end of the model number of the ZIP chip? That would be a 100ns chips, which is too slow for 486 systems, at least at FSB33. You might try to lower the FSB to 20 or 25MHz to check whether the module is detected that way.

I think it's -70 per the label on the back

Either way, is there any advantage other than possibly cost to build a 72-pin SIMM like this? Is it analogous to 9 vs. 3 chip 30-pin SIMM, and in (C) 1995 per the board wouldn't 4MB, 72-pin SIMMs be down to commodity pricing?

edit: could there have been some other device like laser printers that took 72-pin SIMMs, but had the same refresh issue as 9 vs. 3 chip?

Possibly space limitations, if the motherboard (or whatever thing used it) only had a single slot for memory.
With that many chips, it could be a load issue for the driver of the memory bus, if you had multiple sticks.

Hardware RAID controller cache buffer.

Etc.

Some bespoke slot with enough voltage, and need for specific timings, where you can expect them to not be crowded together.

i will try to get it working