Anyone know about 486 motherboards and memory types?

[aswedc]

I got a couple 486 boards around and I'd like to get one of them up with at least 32MB of RAM. They all have 72 pin SIMM slots. I have a couple matched pairs of 8MB and 16MB SIMMS. None of the boards would post with the 16MB sticks, and while all the 8MB ones worked they would only report 8MB while there were two matched 8MB sticks installed. Am I using the wrong type or are they configured wrong? Thanks.

 

[Peter]

You might have EDO DIMMs there and a board that doesn't support them. Also, some late 486 boards already wanted the DIMMs in matching pairs.
What mainboard do you have there, and what chipset is on it?

 

[aswedc]

What memory type would there be other than EDO? I am installing the sticks in matching pairs, that is the problem - the boards only seem to recognize the first one of each pair. I have a couple of these but they're all exhibiting the same behavior

Boards include:
DFI G486-EVB Chipset marked EFAR EC802GL
PAT48AN (Manufacturer not marked) Chipset ALI M1429
Completely not marked Chipset SiS 85C461
UM4980 (Manufacturer not maked) Chipset UMC UM8498F (Don't think this one works at all)
Completely not marked Chipset Opti 82C801

Memory: Two of the memory sets are marked 16MB EDO, the other "2x32" and one unmarked.

Thanks

 

[Peter]

SiS started putting EDO support in with the 496C chipset. On your boards, I wouldn't expect EDO support to be there on any of them.

 

[DusterAZ]

You need FPM SIMMS, fast-page memory. This is what was used before EDO.