Photos of the memory modules would be more informative.

Are they double sided or single sided simms? Are they FPM or EDO? Do you know if they're parity, non-parity, ECC or non-ECC? Do you know what speed they're rated at? I think it would be easier if you let us know the make and model of your simms 😉.

Sorry guys, I focused on the pictures and forgot to write any information about them. This is the exact model I have:

Manufacturer Kingston
Manufacturer Part #
KTH-32000/486
Memory Type Simm
Capacity 32MB
Pins 72 Pin
Bus Type FastPage
Error Correction Parity
Memory Speed 60ns
Voltage 5

I'll post some pictures as soon as I can!

Pingaloka wrote:

Sorry guys, I focused on the pictures and forgot to write any information about them. This is the exact model I have: […]
Show full quote

Sorry guys, I focused on the pictures and forgot to write any information about them. This is the exact model I have:

Manufacturer Kingston
Manufacturer Part #
KTH-32000/486
Memory Type Simm
Capacity 32MB
Pins 72 Pin
Bus Type FastPage
Error Correction Parity
Memory Speed 60ns
Voltage 5

I'll post some pictures as soon as I can!

Are you using a single 32MB simm? I know some older systems needed them to be installed in pairs and it might even be possible that your motherboard doesn't support 32MB per simm slot.

Do you know the make and model of your motherboard?

Ok, another important info. The Ram did work and one point. So it does support a single 32mb SIMM.
In case the RAM is broken, could I buy EDO SIMM or does it have to be FP?
I cannot find any info on the board at all. But here are some pictures.

Pingaloka wrote:

Ok, another important info. The Ram did work and one point. So it does support a single 32mb SIMM.
In case the RAM is broken, could I buy EDO SIMM or does it have to be FP?

You could try scrubbing the contacts with a cotton bud/Q-tip dipped in isopropyl (aka rubbing alcohol). If you replace the RAM then it's probably best to stick with FPM simms as you already know they're compatible. EDO might work (it worked with my old 100MHz 486DX4), but there's no guarantee.

PowerPie5000 wrote:

Pingaloka wrote:

Ok, another important info. The Ram did work and one point. So it does support a single 32mb SIMM.
In case the RAM is broken, could I buy EDO SIMM or does it have to be FP?

You could try scrubbing the contacts with a cotton bud/Q-tip dipped in isopropyl (aka rubbing alcohol). If you replace the RAM then it's probably best to stick with FPM simms as you already know they're compatible. EDO might work (it worked with my old 100MHz 486DX4), but there's no guarantee.

Tried rubbing with cotton...sadly I think the ram is gone.
I was asking for EDO because it seems cheaper and easier to find than FP. Oh well, thanx a lot guys!

If I understand correctly from the pictures, that 32MB SIMM is the only thing in the system, right? So it's detecting 2MB of memory out of the 32MB. It's seeing the module, just not all of it's capacity.
That sounds to me like a compatibility issue. When a motherboard chipset or BIOS doesn't support the logical chip layout of a memory module, it frequently results in only seeing a fraction of the full capacity.

SIMMs don't use a modern SPD EEPROM, the motherboard detects their size and speed by detecting a sequence of +5v or GND on a few pins. It's a limited way of doing it.
According to the info on this site:
http://www.interfacebus.com/Memory_Modules_72 … IMM_PinOut.html
It looks like 2MB and 32MB are both coded the same. I'm not familiar with how that situation is supposed to be handled, but it would seem your motherboard might not be able to tell the difference between 32MB and 2MB.
If the board can electronically support 32MB SIMMs, then maybe with a suitable BIOS it would exhaustively test them to tell the difference.

shamino wrote:

If I understand correctly from the pictures, that 32MB SIMM is the only thing in the system, right? So it's detecting 2MB of me […]
Show full quote

If I understand correctly from the pictures, that 32MB SIMM is the only thing in the system, right? So it's detecting 2MB of memory out of the 32MB. It's seeing the module, just not all of it's capacity.
That sounds to me like a compatibility issue. When a motherboard chipset or BIOS doesn't support the logical chip layout of a memory module, it frequently results in only seeing a fraction of the full capacity.

SIMMs don't use a modern SPD EEPROM, the motherboard detects their size and speed by detecting a sequence of +5v or GND on a few pins. It's a limited way of doing it.
According to the info on this site:
http://www.interfacebus.com/Memory_Modules_72 … IMM_PinOut.html
It looks like 2MB and 32MB are both coded the same. I'm not familiar with how that situation is supposed to be handled, but it would seem your motherboard might not be able to tell the difference between 32MB and 2MB.
If the board can electronically support 32MB SIMMs, then maybe with a suitable BIOS it would exhaustively test them to tell the difference.

So maybe changing some values in the bios itself could solve the problem?

Pingaloka wrote:

So maybe changing some values in the bios itself could solve the problem?

I have no idea. I remember having that AMIBIOS on my 486, but it was so incredibly long ago. And I had no clue about anything back then anyway. 😀

Maybe there's a BIOS setting to enable large vs small size SIMMs (to tell apart the sizes which have the same signaling).
I don't know how it's supposed to be done. It makes me wonder whether motherboards are normally able to handle both sizes. Maybe a board that supports 2MB SIMMs doesn't support 32MB, and vice versa.

--
Not sure how relevant it is, but I looked at the Intel manual for a Pentium Pro board I have that uses FPM SIMMs, and it supports module sizes from 4-32MB. So it seems at least for that board, it can't distinguish between 2 vs 32, thus 2MB not being supported on it.

I agree with Mr. Pie that it seems unlikely a 32 MB SIMM would have ever worked on its own. SIMMs are often only supported in very specific configurations; you should try to track down the manual to be sure.

Jorpho wrote:

I agree with Mr. Pie that it seems unlikely a 32 MB SIMM would have ever worked on its own. SIMMs are often only supported in very specific configurations; you should try to track down the manual to be sure.

Yes, but the thing is, this memory worked before in this same computer. It is only when I took it out and put it in again that it stopped working.

Aye, it's just that I've had days when I've tried to get something working that never actually worked at all even though I'm sure it worked once. Those are bad days. 🙄

I don't think anyone's mentioned that it might depend on which of the four slots you're inserting the SIMM into. It might only support 32 MB in slot 0 and not in slot 3.

Jorpho wrote:

Aye, it's just that I've had days when I've tried to get something working that never actually worked at all even though I'm sure it worked once. Those are bad days. 🙄

I don't think anyone's mentioned that it might depend on which of the four slots you're inserting the SIMM into. It might only support 32 MB in slot 0 and not in slot 3.

Yeah, is one of those days! Just got the 486 and I'm not able to do anything with it.

I have tried all slots with no luck! The guy I bought the computer from has sent me 16mb SIMM FPM memory free of charge. It will arrive in a couple of days. Then we'll see what is happening here!

Be very careful with static electricity whenever you handle stuff 😀
Broke some motherboards and rams like that ...

****EDITED****

I tried a bit of searching. There was some guy on Google Groups who seems to have the same board and notes that its ID string is 12/08/94--2A4X5H02-00 . That led me to http://www.wimsbios.com/biosupdates/pcchips.jsp , which says that it uses a UMC 8881E/8886B chipset. The trail kind of goes cold there. 😒 http://redhill.net.au/b/b-bad.html actually suggests that with those stickers, it's probably PCChip's own crappy formula.

I did find http://motherboards.mbarron.net/models/486pci/4vip3.html , which looks sort of the same. http://motherboards.mbarron.net/models/486pci/4vip3.txt.html does suggest that you might need to configure the jumpers for use with one SIMM per bank.

Jorpho wrote:

I tried a bit of searching. There was some guy on Google Groups who seems to have the same board and notes that its ID string is 12/08/94--2A4X5H02-00 . That led me to http://www.wimsbios.com/biosupdates/pcchips.jsp , which says that it uses a UMC 8881E/8886B chipset. The trail kind of goes cold there. 😒 http://redhill.net.au/b/b-bad.html actually suggests that with those stickers, it's probably PCChip's own crappy formula.

I did find http://motherboards.mbarron.net/models/486pci/4vip3.html , which looks sort of the same. http://motherboards.mbarron.net/models/486pci/4vip3.txt.html does suggest that you might need to configure the jumpers for use with one SIMM per bank.

JUMPERS! My worst Nightmare!

Jorpho, amazing research! Thanx for the info, I was having a hard time to identify this motherboard, but it seems you have founded!

From what I can read this is truly a crappy motherboard! It looked so nice when I unpacked the computer...

I can also read that this motherboard supports "Large Disk DOS Compatibility" does that mean over the 500mb limit?

I'm surprised that supossedly being so bad it is still functional after 20 years!

Oddly enough jumpers J23 which are in control of SIMM settings, don't show in my motherboard!

Ok guys, after reading about these "cute" Pcchips boards, and after Ram not being detected, another big question comes up.
FAKE CACHE?

Oh! what a big box of surprises I'm getting with this new computer!