30 Pin SIMM

[triplej]

Trying to upgrade my old Gateway 486/33c, I have 8MB ram installed using 8 ram chips. I guess that makes each chip 1MB. Is it possible to add say 32MB more memory by using 4MB chips in the remaining 8 empty slots for a total of 40 MB.Also I noticed that the CPU is a 486DX according to info on data card located on the back of the sys case no information on the CPU queston,The coprocessor slot is empty is this normal for a 486DX and how can I tell if this CPU is a DX chip?

Thanks in advance
triplej

[Paleo Pete]

You should be able to add more memory in the extra slots, if you can find it. 30 pin memory is rare these days. You might have to swap them depending on how the machine reads memory. In some cses you have to have the larger ones in the first bank, or maybe it's the other way around...Try it and see, if it doesn't read, swap the 1MB chips for the 4MB chips, try it, then add the 1MB chips in the secondary bank and see what happens. But whicever way it works, if you have to swap at all, try one at a time, not both all at once, then add more. It will make life easier if you have trouble with it.

If the heatsink on your CPU is removable, the type is printed on top of the chip, it will say DX or SX. I'm not positive about a 486, but the first boot screen should also display CPU info, as well as the second screen with the rectangular system info box. The [Pause] key will hold either screen so you can read it, any other key will resume booting. If the heatsink is glued to the CPU don't try to remove it. You're more likely to damage the CPU than not.

If you pull the chip out of the socket it might also be stamped on the underside, I just looked at a 486-33DX that is marked on top and bottom, and I think the 486-66DX is also, but it's in a machine, can't check it.

The math coprocessor socket was for machines using the SX chip. The SX is actually a DX chip that didn't meet QA standards, the math coprocessor was disabled, and the chip sold as an SX, at a lower price. Intel did this to be able to market a large number of DX chips that were not up to quality standards.

The "Math Coprocessor" for these chips that goes in the other socket is actually a DX chip that disables the existing SX chip and takes over, and is a full DX chip...so why bother, go for a DX chip in the primary slot to begin with. If you now have a DX chip, don't worry about it, the math coprocessor is built in.

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[triplej]

Thanks Paleo for the information the links are also great I bookbarked for later information.

[triplej]

HELP, I found several 1MB modules but unable to get the sys to read them.
After I installed the first two, sys failed to boot so installed two more sys booted but only read 8MB. Installed 4 more to fill up all banks sys booted up but read only the 8MB. If I remove one of the first sticks that come with the sys I get a configuration error.

Thanks
triplej

[Rick]

You MUST install simm's in order by the socket number.
ie: 0,1,2,3,4,5,6,7
The system was able to boot before adding the extra ram correct?
if so thenthe problem is with the new ram.

pull the ram from slot 4,5,6,7
Keep them sorted.
readd the simm's from 6+7 and reboot.
With a 486 you can even add one simm at a time.
Boot up after each simm is installed.
When it fails to boot remove the last simm added and mark it as Bad.

Remember also to enter the Bios setup with each reboot and allow the system to read and adjust it's setting for the new memory

[triplej]

Thanks for the response.
Problen now is this,after all slots are full all 16 of them sys boots just fine however it still reads only 8MB ram installed. I go into setup but only the 8MB are read there also. Setup does not change after insertion of more sticks.Queston ? why is it that when I install 2 sticks in slot 5 no boot but after I install 2 sticks in slot 6 sys boots OK that makes total of 12 1MB modules in sys and only shows 8MB.You would think if memory was bad sys would fail to boot?

Thanks for your help
triplej