The first board in the picture with the OPTi 495SLC chip might be troublesome. I've heard those board suffer from serious VLB incompatibilities and were corrected with the 495XLC and 495SX chipsets. The second board you have is ISA only but looks pretty solid to me. The Speedstar 24X is a pretty quick card for ISA, so that would be a decent combination. I had an all ISA 486 way back when and it was only a problem when you wanted to run Windows 3.1 apps in higher resolutions with more than 256 colours. For the record, many of the games for Windows 3.1 required you to revert to 640x480x256 anyway. The Cirrus VLB is probably the way to go if you can get it going on the 495SLC board however.

3 chip SIMMs should be parity. Generally 9 chip SIMMs are more compatible, but I've never had a problem with 3 chip SIMMs on 486 systems. I think it was more of an issue for early 386 and 286 systems.

GeorgeMan wrote:

As a young guy, I want to learn how the original DOS/windows 3.1 experience was

#1: stop using the internet, and use only locally available information sources such as hearsay, and paper prints.

I find that with a DX2-66 you lose a lot of performance with an ISA card.

The storage controller likely does little difference for old DOS games to be honest. So for the video I would definitely get a VLB card.

Gabucino you can do some benchmarks. 3dbench is very sensitive about the graphics performance.

Anonymous Coward wrote:

The first board in the picture with the OPTi 495SLC chip might be troublesome. I've heard those board suffer from serious VLB incompatibilities and were corrected with the 495XLC and 495SX chipsets. The second board you have is ISA only but looks pretty solid to me. The Speedstar 24X is a pretty quick card for ISA, so that would be a decent combination. I had an all ISA 486 way back when and it was only a problem when you wanted to run Windows 3.1 apps in higher resolutions with more than 256 colours. For the record, many of the games for Windows 3.1 required you to revert to 640x480x256 anyway. The Cirrus VLB is probably the way to go if you can get it going on the 495SLC board however. 3 chip SIMMs should be parity. Generally 9 chip SIMMs are more compatible, but I've never had a problem with 3 chip SIMMs on 486 systems. I think it was more of an issue for early 386 and 286 systems.

The ram came preinstalled on the motherboards, so I guess it's ok. But I wonder why the VLB board shows .25MB less ram. I didn't know about the 495SLC and the Win 3.1 256 color thing, will research a little until the rest hardware arrives.
Hmmm, what about the Tseng card? I thought it was faster than WD.

Gabucino wrote:

GeorgeMan wrote:

As a young guy, I want to learn how the original DOS/windows 3.1 experience was

#1: stop using the internet, and use only locally available information sources such as hearsay, and paper prints.

Well, I guess that was the point back then. At my childhood I also didn't have internet and the first years I was buying PC and PSX magazines like crazy.
But nowadays nobody speaks about old stuff, so I don't think I will find any info locally... 😵 By saying "experience", I mean something like: not having even a PS/2 mouse, trying to get such old hardware going etc etc.

Mau1wurf1977 wrote:

I find that with a DX2-66 you lose a lot of performance with an ISA card.
The storage controller likely does little difference for old DOS games to be honest. So for the video I would definitely get a VLB card.

Now that you mention it, I observed that the 486DX2 gets pretty damn hot quickly, but the 486DX does not. I don't think I want to run it without a cooler attached, but I don't seem to find a way to actually attach one. 🤣
I guess that the CPUs are interchangeable and compatible with both boards, but one 486DX4/100 is not as there are no voltage regulators on the board itself. 😢

What about the HDD limits on these? I tried to manually set thw CHS info on the BIOSes and both of them allowed values above 504MB to be displayed. Does that mean that they'll work with HDDs/CFs uo to 8GB or I must try to see?

To confirm the voltage I found this guide ages ago. Man I really need to print all this out and store it properly 🙁

My mainboard auto-selects the voltage and using a voltmetre and shorting a pin or two you can test this behaviour.

But my board does have a voltage regulator.

There are 48 clip-on coolers, but most use a glue that comes from Krypton 😀

With storage capacity, mine also detects a 2GB flash card for example (19xx something). But when you partition it it ends up as a 500 something partition. Not a big deal.

If you want more there are various options. Drive overlay software (I could never source one), a dedicated storage controller (also hard to find), an upgraded BIOS (also hard to find) and translator cards (never seen one on eBay).

Or you can go SCSI, they are quite easy to obtain...

GeorgeMan wrote:

The ram came preinstalled on the motherboards, so I guess it's ok. But I wonder why the VLB board shows .25MB less ram. I didn't know about the 495SLC and the Win 3.1 256 color thing, will research a little until the rest hardware arrives.
Hmmm, what about the Tseng card? I thought it was faster than WD.

About the 256 missing kB: My guess would be that this is because of BIOS shadowing/RAM relocation. Maybe the two boards do things different, or the BIOS settings are different.

The Tseng card and the WD90C31 are probably quite similar. We had a WD90C31 (Paradise branded) in our 386, worked great for games and Win31, I don't think another card would be faster. The Tseng card might be faster for read accesses which usually don't matter. (Maybe for a GUI that doesn't use acceleration features.)

GeorgeMan wrote:

Now that you mention it, I observed that the 486DX2 gets pretty damn hot quickly, but the 486DX does not. I don't think I want to run it without a cooler attached, but I don't seem to find a way to actually attach one. 🤣

IIRC DX2/66 usually came with a passive heatsink.

Mau1wurf1977 wrote:

To confirm the voltage I found this guide ages ago. Man I really need to print all this out and store it properly :( My mainboar […]
Show full quote

To confirm the voltage I found this guide ages ago. Man I really need to print all this out and store it properly 🙁
My mainboard auto-selects the voltage and using a voltmetre and shorting a pin or two you can test this behaviour. But my board does have a voltage regulator.
There are 48 clip-on coolers, but most use a glue that comes from Krypton 😀
With storage capacity, mine also detects a 2GB flash card for example (19xx something). But when you partition it it ends up as a 500 something partition. Not a big deal.
If you want more there are various options. Drive overlay software (I could never source one), a dedicated storage controller (also hard to find), an upgraded BIOS (also hard to find) and translator cards (never seen one on eBay). Or you can go SCSI, they are quite easy to obtain...

Without a regulator, I'm limited to 5v. So I'' never be able to fit the DX4-100Mhz part into one of these boards. I have another very small size PCI 486 board that accepts it, but it doesn't want to boot, so I'm stuck on this 😢
I think that 500MB partition is enough for windows 3.1. I'm receiving tomorrow the rest of the stuff but I'm still waiting for the CF_IDE adapter from ebay to arrive.
Trial and error is the solution, together with help from you guys! 😊
I don't want to go SCSI. Perhaps 2nd half of 2014 or so...

idspispopd wrote:

About the 256 missing kB: My guess would be that this is because of BIOS shadowing/RAM relocation. Maybe the two boards do things different, or the BIOS settings are different.
The Tseng card and the WD90C31 are probably quite similar. We had a WD90C31 (Paradise branded) in our 386, worked great for games and Win31, I don't think another card would be faster. The Tseng card might be faster for read accesses which usually don't matter. (Maybe for a GUI that doesn't use acceleration features.)
IIRC DX2/66 usually came with a passive heatsink.

Will buy a cooler with clips from ebay. Till then, I don't even have a case to put them, so a random cooler just put on them on the desk is ok for testing!
Also will try to find the best options in the BIOS, which is not so easy because they are much diferrent from the ones found in newer BIOSes and I'm not used to them...! 🤣
Hopefully that will solve the 256KB "lost" ram!

The VLB motherboard died just an hour ago unfortunately...!

I booted from floppy, run speedsys, everything was ok. I changed VGA a couple of times, and then it failed to boot.
Till now, no beeps on speaker, no nothing! What can have gone so bad that it died? 🙁 🙁

GeorgeMan wrote:

The VLB motherboard died just an hour ago unfortunately...!

I booted from floppy, run speedsys, everything was ok. I changed VGA a couple of times, and then it failed to boot.
Till now, no beeps on speaker, no nothing! What can have gone so bad that it died? 🙁 🙁

I would remove power cables and check every pin with multimeter. Or a faster approach: Try another PSU.

carlostex wrote:

GeorgeMan wrote:

The VLB motherboard died just an hour ago unfortunately...!

I booted from floppy, run speedsys, everything was ok. I changed VGA a couple of times, and then it failed to boot.
Till now, no beeps on speaker, no nothing! What can have gone so bad that it died? 🙁 🙁

I would remove power cables and check every pin with multimeter. Or a faster approach: Try another PSU.

PSU works on other machine, as well as VGA and CPU. 🙁

Overcoming the fact that the VLB mobo is dead, I installed the DX2/66 CPU onto the UMC mobo and it worked.
I also plugged in an ISA single IDE multi controller, the Tseng ET4000AX vga and a SB Vibra 16S.
Installed DOS 6.22, CTCM to configure the Vibra on the non-PnP mobo/OS, vibra drivers and got it playing 64kbps 22KHz stereo mp3s with ~70% cpu load under DOS!
It was my first time using such an old machine, installing DOS not on a virtual machine and configuring them all! Even the CD-ROM on the Vibra sound card is working under dos!

Then I moved to the next step: From withing DOS and working CD-ROM, I installed windows 3.1 and using a keyboard with integrated touchpad (RS232), I even had a working mouse pointer! Not to mention how fast the Win 3.1 system feels, although running on such old hardware!

Totally imressed! 😁 I desperately need to find an AT case for that... but I don't really know where... 🙁