what chips do they have on them? whats the model and markings?

There are nine Samsung KM41C16000CK-6 on each module. Datasheet says they are CMOS 16M x 1bit 60ns FPM memory chips. SIMMs PCBs are unmarked/generic.

Youre right, and they are 5v.
Well if they do not work in any system and you cannot make use for them, i would return them.
Do you have a manual for those boards and the brand ram chips they maybe support in a compatibility view.
Or you might want to install them in the awe32.
Where did you get them, and what did you pay for them?

NJRoadfan wrote:

My Tyan S1437 and NICE EISA boards officially support them and use the SiS 411/406 chipset.

What do you mean by that? Does it explicitly say in the manuals that they support 16MB SIMMs in any and all slots?

If the board does not support having four SIMMs in all four slots at once, it might support two SIMMs in two specific slots.

No manuals for any of the boards outside of TH99 and mbarron.net. I doubt this particular memory chip was around in 1993 to check compatibility!

I got them off ebay from a memory vendor NOS. At $8 a piece they weren't cheap. I'll have to get an RMA and hope they accept a return and understand that I'm using 20 year old equipment from defunct companies.

Jorpho wrote:

What do you mean by that? Does it explicitly say in the manuals that they support 16MB SIMMs in any and all slots?

If the board does not support having four SIMMs in all four slots at once, it might support two SIMMs in two specific slots.

Both boards have 16x30-pin SIMM slots and officially support 256MB total RAM. 4x16MB SIMMs is a supported configuration.

http://motherboards.mbarron.net/models/486vlb … isa-vp.txt.html

> If the board does not support having four SIMMs in all four slots at once, it might support two SIMMs in two specific slots.

A 486 needs 30-pin SIMMs in groups of 4. 32-bit processor bus vs 8-bit on the SIMM.

I am using 16MB SIMMs in my Super EISA board. They are also 9 chip 60ns, but I believe they are made by Samsung. The way they are supported is a little pickier than smaller density SIMMs. You have to start with bank 0, then bank 1, bank 2, bank 3 etc. I also noticed they can't be mixed with lower density SIMMs...in my case the lower density SIMMs were simply not detected. Have you tried using four of these SIMMs in bank 0 with no other SIMMs installed?

Anonymous Coward wrote:

I am using 16MB SIMMs in my Super EISA board. They are also 9 chip 60ns, but I believe they are made by Samsung. The way they are supported is a little pickier than smaller density SIMMs. You have to start with bank 0, then bank 1, bank 2, bank 3 etc. I also noticed they can't be mixed with lower density SIMMs...in my case the lower density SIMMs were simply not detected. Have you tried using four of these SIMMs in bank 0 with no other SIMMs installed?

Yes, 4x16MB in bank 0, all other banks empty. Your photos show 5-chip SIMMs, a different layout. I would think a board this new would have no problems with 16Mx1 density chips.

No, they're not 5 chip. The other four chips are on the back side.

Some late night testing found the problem. I appear to have a defective SIMM, time to RMA things. Creative's memory tester when the questionable SIMM is installed only detects a fraction of the RAM. Any combination of the other three detects the full 28MB. Damn that was an annoying problem.

Good thing you have that awe32 and it is capable of testing 2x8bit ram, or 9bit in your case.
As a 386sx would not be able to test the 2x16mb simm.

Memory has been RMA'ed, now the waiting game begins again.

RMAed SIMM came in. Its not the same type of module as the other three, but has the same Samsung DRAM on it. Machine POSTs not, but something still isn't working right. The BIOS memory test stops at 32MB unless I bypass it. Memtest86 crashes and burns as well. All seems to test fine on the AWE32 though. I'm going to just ask for a refund at this point. So much for 64MB of RAM in the 486.

Lots of people have 64MB (or more) DRAM on their 486 motherboards, but usually using 72-pin SIMMs instead. 16MB 30-pin SIMMs are a rather unique way of getting there.

I don't know what to say. I have the same motherboard with the same BIOS, and 16MB 30-pin SIMMs with samsung DRAM. I have 128MB installed and it works great.

Anonymous Coward wrote:

Lots of people have 64MB (or more) DRAM on their 486 motherboards, but usually using 72-pin SIMMs instead. 16MB 30-pin SIMMs are a rather unique way of getting there.

I don't know what to say. I have the same motherboard with the same BIOS, and 16MB 30-pin SIMMs with samsung DRAM. I have 128MB installed and it works great.

I have a feeling this memory is dodgy overall. All three of my 486 motherboards with 30pin SIMM slots exhibit the same behavior, so its not the SiS 406/411 chipset causing the problem. If they don't refund my money, my last ditch effort will be to have them send me another matched set of 4 SIMMs. Otherwise I'll likely sell them paired as memory for AWE32 cards as they seem to work perfectly fine in that application!