A 386SX is probably well equipped with 4MB RAM, everything that needs more RAM will run slow on that CPU anyway. I do understand the urge to upgrade everything to the maximum, though. You'd probably end up using the RAM for disk cache mostly.
I wouldn't bother with the coprocessor. Not important for games until Pentium, and most programs that would profit from a 387 would probably run better on a 486. But this has been discussed before.

The reason I want to upgrade the ram is because I have installed windows 95 on the machine, I wanted to see how usable the computer is with 95 with a decent amount of ram, I have noticed that a few games run faster in windows 95 than they did in Windows 3.1, notably asteroids from the Microsoft Arcade Collection, my guess is that the windows 95 Tseng driver is better than any Tseng driver avliable for windows 3.1.

95 on a 386-16?? OH MY GOD

Anyway I am surprised the limit is so low. I have a Compuadd 486DX/33 and it will take 64MB of RAM

Only way to know is get some 30 pin simms and try them

That is one sexy looking PC desktop case 😀

I order a 4x4mb 16mb kit thinking that i would get FPM and got EDO modules.
The system would not post, do you think the problem is that the system is completely incompatible with EDO?
The chips on the modules are Toshiba TC5117405CSJ, I found a part number cross reference that indicated the TC5117405 means that they are 4m x 4bit EDO chips and the equivalent fast page part number is TC5117400.
http://www.ebay.com/itm/4x-4MB-16MB-30pin-SIM … =item2a2b4916d8

Half-Saint wrote:

That is one sexy looking PC desktop case 😀

I can't see the pictures, why can't I see the pictures? 😲

There aren't any pictures.
But a quick google will find you some.

I bought some 386sx SBC's for a few $10 to steal the 3 chip 4MB simms off of and when i put them in the compuadd it starts up with the first 64k failure beep code.

i486_inside wrote:

I bought some 386sx SBC's for a few $10 to steal the 3 chip 4MB simms off of and when i put them in the compuadd it starts up with the first 64k failure beep code.

Are you sure they are regular FPM ram sticks?

Personally I would rather spend a little more and know what I am getting. This is where I got the 30 pin simms for my Compuadd 486:http://www.oempcworld.com/

Although the first set I got had 2 corroded sticks and had to be returned.

I have tried moving sticks around, and managed to get it to post sucessfully but it only recongnized the 2x4mb sticks as 1mb each, then I added two other stick then the system booted with some garbage on the screen and said soething abour parity error and the system was unresponsive to input, and I've tried moving the stick around sometimes it throws out DMA errors other times memory errors.

If i put pressure on the sticks in the slots i could make it post but the coputer would only recognixe 4MB even though there is 16mb installed.
either there are only 22 connected address lines, there is a chipset limitation, or a bios limitation.

Is it also possible that the problem is that I am using 3chip 4MB simms and the original 1MB simms are 9chip

Any chance you have the dip switch settings for the Compuadd 316s? Trying to upgrade to 4mb.. Thanks!

funcle wrote on 2022-08-02, 23:05:

Any chance you have the dip switch settings for the Compuadd 316s? Trying to upgrade to 4mb.. Thanks!

To my knowledge there were no dip switch configurations, you'll need a setup floppy for a 386 Phoenix or AMI or whatever type of BIOS this has, it's been years since I've messed with this so I don't remember exactly what BIOS setup floppy I used. Although there may have been a rudimentary setup you can get to if you force an error like holding down a key and getting a stuck key error or removing the cmos battery and getting an invalid checksum error. But I don't remember if that basic setup allows you to change the memory size like you can with the boot floppy.

Thanks, I think my simms are mixed and that's the problem. I'll dig out some more and try again. Amazingly the miniscribe 40mb HDD still works and all the original software and utilities are there!

I found the issue.. a set of jumpers under the IDE cable I hadn't noticed.. J14-J17 needed to be set to pins 1 & 2 for 4mb of ram.

I had 95 on a DTK 386sx-25

Slow but not unusable for business tasks.

Although rare a 386sx with cache is usually a lot faster in 95, if you get good ram try to set 0 wait states.

I’ve found many SX systems seem to puke out above 12mb of ram, it depends on your 16 bit perepherals and the system itself.