RagingSquirrel wrote on 2024-02-14, 09:25:

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Hi

I am building a retro config with an Amd 486 100 Mhz processor with 16 MB edo ram , and a Tm-486sps motherboard. I already Installed Dos 6.22 and Win 3.11 , but when i install Win 95 on the boot process i got this error message

While initializing device VXDLDR Windows protection error. You need to restart your computer

I tried to research the problem, but almost all the topic i read is about virtualizing Win 95 on a modern hardware.. where they say its because the cpu is too fast. Well not in my case for sure.. I wonder does anybody had the same error , also what could cause it?

Hello

I think your system is unstable. In General, the installation of Win9x itsself is a very good stability test. Running DOS and Win3.11 is less demanding.
So "system" here is mainly: mainboard, cpu, cache and RAM.
You wrote, you use 16MB EDO ram. If this is true, then remove the RAM and use FPM RAM. NO EDO.
Only very few 486 mainboards support EDO RAM, the vast majority of boards does not.

Hey.. Thank You for your reply.. on other forums they suggested to do a memory test using memtest86+ .. My problem is that tm-486sps only have 72 pinn edo ram slots..
I do have an other processor indtead of 486 dx 4 100 mhz i got a 486 sx 33 , i will try with that.. but for futhurer investigation i do have to buy eighter a new motherboard , or new rams .. or maybe both

RagingSquirrel wrote on 2024-02-14, 16:20:

Hey.. Thank You for your reply.. on other forums they suggested to do a memory test using memtest86+ .. My problem is that tm-486sps only have 72 pinn edo ram slots..
I do have an other processor indtead of 486 dx 4 100 mhz i got a 486 sx 33 , i will try with that.. but for futhurer investigation i do have to buy eighter a new motherboard , or new rams .. or maybe both

omfg
There are no 72pinn edo RAM slots.
You have 72 pin SIMM slots.
There is a 72pin FastPageMode (FPM) RAM and there is 72pin EDO RAM.
So what do you have?
In case you don't know it, you can make a picture of your RAM modules.
Also you can make a picture of your board, that we can clearly see the writing on the SIS496 and the SIS497 chip.

Hey.. Thanks for your "kind" answear. My bad it is a 72 pin EDO RAM , also here is the photo from the mother board chips.. I also runned a memtest durring a whole night but didnt catched any error .. it has more that 20 pass and no fail at all, so i think the rams are ok ..

RagingSquirrel wrote on 2024-02-15, 14:42:

Hey.. Thanks for your "kind" answear. My bad it is a 72 pin EDO RAM , also here is the photo from the mother board chips.. I als […]
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Hey.. Thanks for your "kind" answear. My bad it is a 72 pin EDO RAM , also here is the photo from the mother board chips.. I also runned a memtest durring a whole night but didnt catched any error .. it has more that 20 pass and no fail at all, so i think the rams are ok ..

Hi. Sorry for being not too friendly. But it is annoying, every 2 days there is a new posting, where somebody tries to run a 486 mainboard with EDO RAM. Noooooooo.
From what I see, your mainboard does not support EDO RAM, you have the "NV" chipset revision.
So change the RAM. Obviously memtest does not catch the error, but the Win95 installation does.

EDIT: Tomato 4DPS v2.1 board not posting

MORE EDIT: Did you intentionally make 2 links in your posting to the same picture? Better would have been both chips sis496 and sis497.
Can you make a picture of your RAM modules, too? Then we can double check, if it is really EDO.

Hi

Thank you for your reply.. Small update, i tyested the videocard and the processor also the pover suply in a different config and they work there.. so it must be eighter the rams or the motherboard itself ... here are the pictures of the ram.. can you tell me please what kind of ramms are these.. Also if they edo ..
if i would order two of this ram modules would it work whit it?

https://www.ebay.com/itm/185809147001?mkcid=1 … emis&media=COPY

Also my bad it was an accident that i copied the same linjk twice heres the photo of the other chip

also i wonder how win 3.11 run perfectly but not win 95 with edo ram, if its not compatible?

Now i am thinking to buy the FPM modules.. or just buy an other motherboard.. obiously the mobo is more expensive but i am really clueles what to do ..

RagingSquirrel wrote on 2024-02-15, 20:33:

Hi […]
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Hi

Thank you for your reply.. Small update, i tyested the videocard and the processor also the pover suply in a different config and they work there.. so it must be eighter the rams or the motherboard itself ... here are the pictures of the ram.. can you tell me please what kind of ramms are these.. Also if they edo ..
if i would order two of this ram modules would it work whit it?

https://www.ebay.com/itm/185809147001?mkcid=1 … emis&media=COPY

Also my bad it was an accident that i copied the same linjk twice heres the photo of the other chip

also i wonder how win 3.11 run perfectly but not win 95 with edo ram, if its not compatible?

Now i am thinking to buy the FPM modules.. or just buy an other motherboard.. obiously the mobo is more expensive but i am really clueles what to do ..

Those SIMMs have these chips https://elcodis.com/parts/5792876/GM71C18163C … .html#datasheet
=> EDO.
They will not work.
Most likely Win 3.11 will not utilize all the RAM, especially when you have 16MB.
I think it will be unstable, too, but not immediately.

AND those in the ebay link are FPM, number of the chips end with 00. They will work.

Yes, those simm modules have EDO capability.

Now where is that vogons thread that talked about how to use EDO ram as FPM by combining two pins on the chips.... ARGH.

the ebay link is FPM

edit: lift /OE and short to /CAS

RagingSquirrel wrote on 2024-02-15, 20:33:

Hi […]
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Hi

Thank you for your reply.. Small update, i tyested the videocard and the processor also the pover suply in a different config and they work there.. so it must be eighter the rams or the motherboard itself ... here are the pictures of the ram.. can you tell me please what kind of ramms are these.. Also if they edo ..
if i would order two of this ram modules would it work whit it?

https://www.ebay.com/itm/185809147001?mkcid=1 … emis&media=COPY

Also my bad it was an accident that i copied the same linjk twice heres the photo of the other chip

also i wonder how win 3.11 run perfectly but not win 95 with edo ram, if its not compatible?

Now i am thinking to buy the FPM modules.. or just buy an other motherboard.. obiously the mobo is more expensive but i am really clueles what to do ..

If you buy modules, I would rather buy without parity and with 60ns.
So more something like this
https://www.ebay.at/itm/185907144468

Thank You for your answer.. I ordered it.. one more question tho.. i was testing my mother board if it boots whitout the cache chips .. and accidentaly i fried one of them ,, that i putted back in the other way around. The board is still booting if i disable external cahe from the bios. So i searched the web for the same chip but couldnt find one .. i wonder if these things ar inter changeable.. could you suggest a replacement chip for this type of cache.. (as i said i am really new tio this. i was 10 years old when i had my 486 and i wanted to rebuild one.. but i have to admit is way harder than building a p3 for example..)

RagingSquirrel wrote on 2024-02-15, 21:58:

Thank You for your answer.. I ordered it.. one more question tho.. i was testing my mother board if it boots whitout the cache c […]
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Thank You for your answer.. I ordered it.. one more question tho.. i was testing my mother board if it boots whitout the cache chips .. and accidentaly i fried one of them ,, that i putted back in the other way around. The board is still booting if i disable external cahe from the bios. So i searched the web for the same chip but couldnt find one .. i wonder if these things ar inter changeable.. could you suggest a replacement chip for this type of cache.. (as i said i am really new tio this. i was 10 years old when i had my 486 and i wanted to rebuild one.. but i have to admit is way harder than building a p3 for example..)

Any SRAM 32kx8 15ns DIP28 should be fine.
like
https://www.ebay.at/itm/325252690343
Those chips are a bit expensive as it seems. You could risk buying it from China, but it takes a long time.

Thank You

I noticed i got one if this with 2*14 pinn and 4 of 2*16 pinn what is the difference? Is it okay if i only change the 14 pinn one since thats the one i got fried.. ?

RagingSquirrel wrote on 2024-02-15, 22:11:

Thank You

I noticed i got one if this with 2*14 pinn and 4 of 2*16 pinn what is the difference? Is it okay if i only change the 14 pinn one since thats the one i got fried.. ?

The 32pin ones (bigger ones) are 64kx8 SRAM chips. That gives you the 256kB cache. The tag ram (32kx8) is for "administration"

EDIT: hopefully nothing got damaged on the board.

Ohh.. dont even mention that..i am so mad about myself for screwing up.. I do hope its only the chip .. as i said if i disable extended cache in the bios it does pass trough the boot sequence, but freez on the Win 95 screen .. while before it i gpot the above mentioned error message.. anyway, i need your help because i really cant diferentiate these chips..
Would any of these work for me?

These ones are 512 k instead of the 256k witch i have that i understand.. according to my mainboards manual it compatible with 512 but i have to rearange a few jumpers..

https://www.vatera.hu/retro-pc-alkatresz-sram … 3342273560.html

These ones doesnt mention how many k s.. but it kind a look like what i have in my mobo..

https://www.vatera.hu/retro-pc-alkatresz-sram … 3344190743.html

These are whole sets and they cost the same as the one chip you sent me .. also they are being saled in my country so i can just grab them on the weekend.. i am also thinking, if i have to buy new chips i might just upgrade to it to 512k if thats possible to do.

I also noticed that is the last two numbers on the chips refer to ns (is that nano sec for some kind of refresh rate? ).. because both the above mentioned chip sets has different number on the 4 bigger than on the one "administration" chip.. is that a problem, or how does it work?

hay .. just a few more thing i noticed.. I keep testing the motherboard if it got damaged, and i cant really tell.. if i take out the 4 cache chip it boots normally (well it boots to dos and Win 3.11.. still not in Win 95), altrrough i read the manual provided in retro web... where it says the 4 cache chipp should work without the TAG RAM if the writeback function is disabled .. so i setted this option on write trough .. sinc there wasnt any disable option.. but its still not boot if any of the chips are in... Also i noticed, that my mobo doesnt have any cache chip jumpers.. where the manual describe it has to be 2 of those 3 pinn jumpers, to set it to 128 256 512 k caches.. now i am really clueles...

RagingSquirrel wrote on 2024-02-16, 09:16:

Ohh.. dont even mention that..i am so mad about myself for screwing up.. I do hope its only the chip .. as i said if i disable e […]
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Ohh.. dont even mention that..i am so mad about myself for screwing up.. I do hope its only the chip .. as i said if i disable extended cache in the bios it does pass trough the boot sequence, but freez on the Win 95 screen .. while before it i gpot the above mentioned error message.. anyway, i need your help because i really cant diferentiate these chips..
Would any of these work for me?

These ones are 512 k instead of the 256k witch i have that i understand.. according to my mainboards manual it compatible with 512 but i have to rearange a few jumpers..

https://www.vatera.hu/retro-pc-alkatresz-sram … 3342273560.html

These ones doesnt mention how many k s.. but it kind a look like what i have in my mobo..

https://www.vatera.hu/retro-pc-alkatresz-sram … 3344190743.html

These are whole sets and they cost the same as the one chip you sent me .. also they are being saled in my country so i can just grab them on the weekend.. i am also thinking, if i have to buy new chips i might just upgrade to it to 512k if thats possible to do.

I also noticed that is the last two numbers on the chips refer to ns (is that nano sec for some kind of refresh rate? ).. because both the above mentioned chip sets has different number on the 4 bigger than on the one "administration" chip.. is that a problem, or how does it work?

There are complete sets of 256kB cache, so very similar to your existing set. The chips with 512 are 64kx8, the chip with the 256 in the number is the 32kx8 tag ram.
The tag ram is faster in both sets, yes. The second set has only 20ns data srams, so that would be slower than would you have now.
Yes, you can upgrade to 512kB Cache, then you need a tag ram 32kx8 (the one with 256 usually in the number) and 4 times 128kx8, for example ISSI IS61C1024-15 .

RagingSquirrel wrote on 2024-02-16, 21:45:

hay .. just a few more thing i noticed.. I keep testing the motherboard if it got damaged, and i cant really tell.. if i take out the 4 cache chip it boots normally (well it boots to dos and Win 3.11.. still not in Win 95), altrrough i read the manual provided in retro web... where it says the 4 cache chipp should work without the TAG RAM if the writeback function is disabled .. so i setted this option on write trough .. sinc there wasnt any disable option.. but its still not boot if any of the chips are in... Also i noticed, that my mobo doesnt have any cache chip jumpers.. where the manual describe it has to be 2 of those 3 pinn jumpers, to set it to 128 256 512 k caches.. now i am really clueles...

tag ram is always needed.
"where it says the 4 cache chipp should work without the TAG RAM if the writeback function is disabled". Where did you find that?
EDIT: Yes, I see, it is in the second manual. That is definitely wrong.

Maybe you can make a high resolution picture of the board (without cables blocking the view), then we might be able to help you with the jumpers.

MORE EDIT:
I would first install the FPM RAM, it does not make too much sense to test something with the wrong RAM type.

CoffeeOne wrote on 2024-02-17, 18:07:

There are complete sets of 256kB cache, so very similar to your existing set. The chips with 512 are 64kx8, the chip with the 25 […]
Show full quote

RagingSquirrel wrote on 2024-02-16, 09:16:

Ohh.. dont even mention that..i am so mad about myself for screwing up.. I do hope its only the chip .. as i said if i disable e […]
Show full quote

Ohh.. dont even mention that..i am so mad about myself for screwing up.. I do hope its only the chip .. as i said if i disable extended cache in the bios it does pass trough the boot sequence, but freez on the Win 95 screen .. while before it i gpot the above mentioned error message.. anyway, i need your help because i really cant diferentiate these chips..
Would any of these work for me?

These ones are 512 k instead of the 256k witch i have that i understand.. according to my mainboards manual it compatible with 512 but i have to rearange a few jumpers..

https://www.vatera.hu/retro-pc-alkatresz-sram … 3342273560.html

These ones doesnt mention how many k s.. but it kind a look like what i have in my mobo..

https://www.vatera.hu/retro-pc-alkatresz-sram … 3344190743.html

These are whole sets and they cost the same as the one chip you sent me .. also they are being saled in my country so i can just grab them on the weekend.. i am also thinking, if i have to buy new chips i might just upgrade to it to 512k if thats possible to do.

I also noticed that is the last two numbers on the chips refer to ns (is that nano sec for some kind of refresh rate? ).. because both the above mentioned chip sets has different number on the 4 bigger than on the one "administration" chip.. is that a problem, or how does it work?

There are complete sets of 256kB cache, so very similar to your existing set. The chips with 512 are 64kx8, the chip with the 256 in the number is the 32kx8 tag ram.
The tag ram is faster in both sets, yes. The second set has only 20ns data srams, so that would be slower than would you have now.
Yes, you can upgrade to 512kB Cache, then you need a tag ram 32kx8 (the one with 256 usually in the number) and 4 times 128kx8, for example ISSI IS61C1024-15 .

I am not gonna lie its a bit confusing. So is it ok if the tag chip has smaller ns number?

https://www.vatera.hu/retro-pc-alkatresz-sram … 3342273560.html

In this one the tag chip is 12ns and the cache cips are 15. This would be better than wat i have now isnt it? Not just because its 512 k but also its lower ns number … i know i should wait for the ram first. But the advertisement gonna expire tomorrow, so i have to buy it before that … but even if it turns out that the motherboard is faulty and i have to buy an other i still can use these cache chips in the other one …

I will send a photo as soon i get home …

Here is the picture from my motherboard

EDIT: The guy whoom i am buying the cache cips from said, that if i dont have jumpers, it means that it might only support 256 k and eighter doenst gonna work with 512k or only 256k gonna be recognised.. Could it be that instead of jumpers it has to be setted in bios?
Eighter way .. i think buying the 512 k would be the best choice .. because price vise its the same...