apricot wrote on 2024-04-27, 11:10:

I'm having trouble trying to upgrade the RAM on my DELL 425s/L […]
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I'm having trouble trying to upgrade the RAM on my DELL 425s/L

According to the manual the machine should take up to 64MB RAM. I am forever stuck with 03360K RAM no matter what sticks I try, its either that or the machine wont post.

When I got the machine it came with a stick of 8MB EDO RAM but the 8MB stick reads as 3360k so I originally thought it had a 4MB stick but when I tried that stick in another 486 it reads as 8MB.

I went on ebay and I bought another stick of EDO RAM 8MB... I installed the memory into the machine and it reads as 3360k just like the other stick did. I tried them both together but the machine didn't like it. I tried a 32MB stick I had and the machine reads it as 4433k

I was then informed that this machine doesn't use EDO RAM so I thought... ah thats why, so I went back onto ebay and bought an FPM stick of 8MB RAM. I get it today and tried it but the machine wont post with FPM RAM. I reseated the RAM the seller says these RAM sticks have been tested.

I'm getting a bit frustrated I can't play certain games because I get RAM errors.

Before I give up on this machine does anybody know if this machine took a specific type of RAM?

It only support 4 & 16MB sticks - https://web.archive.org/web/19970805021606/ht … 6L/00000015.htm. Also...

Memory

Architecture - nonparity

SIMM sockets - 4

SIMM capacities - 4 and 16 MB

Standard RAM - 4 MB

Maximum RAM - 64 MB

Memory access time:

tRAC - 70 ns

tCAC - 20 ns

External cache (optional) - 128 KB, direct-mapped, look-aside, SRAM card

very early 486 so definitely no EDO. Sometimes EDO works at first in unsupported 486 boards, but then you discover instability and glitches. Countint half the ram might be one of those glitches.
I would try another FPM module, from another seller 😀 or borrowed from someone local to you.

apricot wrote on 2024-04-27, 11:10:

I'm having trouble trying to upgrade the RAM on my DELL 425s/L […]
Show full quote

I'm having trouble trying to upgrade the RAM on my DELL 425s/L

According to the manual the machine should take up to 64MB RAM. I am forever stuck with 03360K RAM no matter what sticks I try, its either that or the machine wont post.

When I got the machine it came with a stick of 8MB EDO RAM but the 8MB stick reads as 3360k so I originally thought it had a 4MB stick but when I tried that stick in another 486 it reads as 8MB.

I went on ebay and I bought another stick of EDO RAM 8MB... I installed the memory into the machine and it reads as 3360k just like the other stick did. I tried them both together but the machine didn't like it. I tried a 32MB stick I had and the machine reads it as 4433k

I was then informed that this machine doesn't use EDO RAM so I thought... ah thats why, so I went back onto ebay and bought an FPM stick of 8MB RAM. I get it today and tried it but the machine wont post with FPM RAM. I reseated the RAM the seller says these RAM sticks have been tested.

I'm getting a bit frustrated I can't play certain games because I get RAM errors.

Before I give up on this machine does anybody know if this machine took a specific type of RAM?

Get a 16MB stick with 8 chips on one side (single sided). Those are most compatible.
EDIT: According to what PC Hoardie found, only 4MB and 16MB sticks work.

Thanks I'll get a 16mb stick with 8 chips single sided.

I might have to get a couple of 4MB sticks.

The ebay listings can be very confusing because they have "EDO then FPM in the title" so I don't really know what I'm getting and by the looks of it the sellers don't know the difference so rather than waste more money I will buy a 4 MB stick to start with and if it works then I'll get another to bring the total to 8MB.

EDO, FPM... Those can be confusing. Lots of sellers even don't know exactly which they sell.
You could try to zoom into the ram chips and search the part no datasheet. This will tell you which it is.

My preferable method is just to stick it in a S7 machine with 72p slots, and it will tell me it it's edo or not. So if you have such a board ready it could help as well. But you'd have to buy the ram first.

I'm my experience most 4MB are fastpage, so 4 of them makes 16MB which is for time that of which a 486-25 typically was equipped with new. It'll be plenty.

if you are up to bending legs and soldering smd then you can modify EDO module into FPM
https://www.youtube.com/watch?v=nk8uEFpYbBw Re: What retro activity did you get up to today?