Both Via KM400/8235 and 741GX/963 offer good compatibility with PCI audio cards, incl. using SBEMU.
Both boards have full 98 driver support but with 8235 you can also enjoy USB 2.0 speeds. On SiS the USB "driver" would just disable the 2.0 controller.
Both of these boards only support AGP 1.5volt. Meaning no Voodoo 3/4/5.
Both of these boards rely on heavy 5V PSU. Point to consider with that Athlon XP 2500+.
Both of these boards are pretty common and not collectible.

Only K7S41GX can undervolt to very low values allowing to run AMD Geode and offers official support for with a BIOS update.
Athlon XP-M has an advantage of on-the-go multi setting (with SetMul or CrystalCPUID) and has in general lower power draw. But you most likely won't be able to run speed-sensitive games from 80's anyway.

To round it up,
Unless you have specific goal to build with 462 parts you might as well go 754 (with VIA and SiS chipsets you get all the same features, some extra like CnQ, and use a modern PSU).
To get more compatibility with DOS games you ideally need both ISA and AGP 3volt (440BX, VIA 694, etc).

Asrock looks to be more limiting: only 2 PCI slots. And one slot will be blocked, if you're planning to use powerful AGP card.

Point taken on Socket 754 being more suitable overall - but seeing as I have these boards now, and microATX S754 seems relatively scarce (at least on eBay UK), it seems worth trying to put together the best compromise with what I have in these Socket A systems ...

Bruno128 wrote on 2023-12-10, 23:40:

Both of these boards rely on heavy 5V PSU. Point to consider with that Athlon XP 2500+.

Well I've certainly hit the power issue ... As the XP2500+ was already in the VIA based board, and in the case, I decided to add a new PSU + hard drive and try out installing Windows 98. All seemed to go well with the integrated graphics including when I added an Audigy card. But when I added a Radeon 9250 AGP, I quickly got some weird/random errors, which ended in a totally corrupted C: partition - I'm guessing because of insufficient power.

The PSU I tried was a beQuiet! 300w SFX, which claims 20A on the 5v rail (but with maximum 103w combined with 3.3v). I guess this actually isn't enough...

Would the mobile version of the XP be likely to have low enough power draw to work with this PSU? Or would I need to search out a PSU with a 5V rating that isn't shared with the 3.3v ?

You can try. Mobile Athlons are specified run under 45w while desktop parts are 70w. Undervolting desktop cpu can get close to but usually mobile CPU are binned better.

XP-M is also multiplier unlocked without modding so it's the better cpu for old games. I would prefer the VIA board because win98 drivers have always worked fine. I don't have experience with SiS chipsets.

justin1985 wrote on 2023-12-12, 23:11:

The PSU I tried was a beQuiet! 300w SFX, which claims 20A on the 5v rail (but with maximum 103w combined with 3.3v). I guess this actually isn't enough...

Would the mobile version of the XP be likely to have low enough power draw to work with this PSU? Or would I need to search out a PSU with a 5V rating that isn't shared with the 3.3v ?

Modern 300W PSU has some protection features but XP 2500+ alone consumes about 70W. Add a simple video card like 9250 and you already push the limit.
Barton XP-M 2400+ is easier in that regard with the power footprint of 45W.
I think it would be smart to rethink your build choices at this point.

Thanks for the advice. I've cleaned up the VIA board (washing with water then blasting with compressed air from an airbrush to drive most water out) and I'll swap the XP-M onto this board to carry on playing around with ...

But I also had an eBay offer accepted on an MSI K8MM3-V microATX S754 motherboard complete with a Sempron 3300+. It still has AGP and DDR1, and MSI have all the Win98 drivers for the K8M800 chipset still on their site, so I guess it still 'feels' of the late Win98 era! The VIA VT8237R southbridge does have SATA - but is this one of the buggy ones that won't work with SATA-II or SATA-III? (which I guess means basically no SSDs?)

justin1985 wrote on 2023-12-13, 12:57:

The VIA VT8237R southbridge does have SATA - but is this one of the buggy ones that won't work with SATA-II or SATA-III? (which I guess means basically no SSDs?)

Yes there is a notorious problem with those, solved in 8237Plus. If you have 8237R version you may still try a trick and create a JBOD RAID array comprised of 1 drive, then it will be detected. Other than that seems a fine small board. We have a note exactly on account of SATA here.

Bruno128 wrote on 2023-12-13, 14:47:

Yes there is a notorious problem with those, solved in 8237Plus. If you have 8237R version you may still try a trick and create a JBOD RAID array comprised of 1 drive, then it will be detected. Other than that seems a fine small board. We have a note exactly on account of SATA here.

Interesting - thank you! From the seller's photo on eBay it isn't possible to read the southbridge chip label (rotating and zooming in, maybe there is a hint of the "Plus" after the number?), but the PCB version number seems to say "MS-7181 VER: 10" where the ones on the RetroWeb page say "VER: 2.0" or "VER: A". It certainly doesn't look like there is a missing . as in "1.0" - but perhaps that is a typo from MSI! I guess I will just have to wait and see when it arrives ...

So if it is the VIA VT8237(R)+, it should work with SATA III drives? And presuming the BIOS IDE mode option works, I guess it should work in Win98? Slightly anxious on this as I remember having no end of problems getting the SATA ports to work with Win98 on a VIA Epia CN (CN700 chipset with, it turns out, VIA VT8237(R) southbridge) ...

justin1985 wrote on 2023-12-13, 15:09:

So if it is the VIA VT8237(R)+, it should work with SATA III drives? And presuming the BIOS IDE mode option works, I guess it should work in Win98? Slightly anxious on this as I remember having no end of problems getting the SATA ports to work with Win98 on a VIA Epia CN (CN700 chipset with, it turns out, VIA VT8237(R) southbridge) ...

If it's the "Plus" version, you won't have any trouble with modern SATA III SSDs. I'm using two of those on my K8V-MX and they work just fine.

For Win98 compatibility, I had to set the SATA controller to RAID mode, and then install the relevant drivers. There may be a way to get native SATA compatibility as well, but I never bothered with that since the RAID approach worked right out of the box.

justin1985 wrote on 2023-12-13, 15:09:

the PCB version number seems to say "MS-7181 VER: 10"

Means "1.0" in MSI lingo.
You are right it's another revision with same footprint albeit differently populated, and the BIOS versioning scheme of its own (the sticker on yours says 130) .
My preliminary research shows you got K8MM3-V ver.1 = K8MM2.
Ver.2 introduced Plus rev. southbridge (change reflected in schemas) but knowing MSI inconsistency it is not impossible some of mid-ver.1 boards were fitted with Plus rev. southbridges so you may be lucky to find one in your purchase.
Files located, split entry is created, if you would ping me for extra info or a hq photo later I'll much appreciate that. Thanks for the clue anyway!

Bruno128 wrote on 2023-12-13, 16:33:

Means "1.0" in MSI lingo. You are right it's another revision with same footprint albeit differently populated, and the BIOS ver […]
Show full quote

Means "1.0" in MSI lingo.
You are right it's another revision with same footprint albeit differently populated, and the BIOS versioning scheme of its own (the sticker on yours says 130) .
My preliminary research shows you got K8MM3-V ver.1 = K8MM2.
Ver.2 introduced Plus rev. southbridge (change reflected in schemas) but knowing MSI inconsistency it is not impossible some of mid-ver.1 boards were fitted with Plus rev. southbridges so you may be lucky to find one in your purchase.
Files located, split entry is created, if you would ping me for extra info or a hq photo later I'll much appreciate that. Thanks for the clue anyway!

Interesting - thanks so much! Certainly happy to send on a photo when I get it.

I notice that both the diagrams on RetroWeb (K8MM3-V ver.1 and K8MM3-V ver.2) have the northbridge chip shown at a diagonal angle, whereas on the photos (both on Retroweb and my eBay listing) show it set square to the CPU. Sure its not significant, but certainly seems like consistency wasn't MSI's strong suit with this kind of thing ...

Squinting at the eBay photo, it does look like the text line below the VIA logo is long and SEEMS to have a space in the middle, perhaps with a capital P and a few more letters after the space? But perhaps wishful thinking ... Fingers crossed it arrives in working condition anyway - I've now got a Hermes\Evri tracking number, so I'm not holding my breath on getting it quickly ...

justin1985 wrote on 2023-12-13, 17:22:

have the northbridge chip shown at a diagonal angle

Heatsink is square, chip underneath is 45deg against.

The MSI Socket 754 board has arrived, and it definitely has the VT8237R Plus southbridge!

Bruno128 wrote on 2023-12-13, 16:33:

Files located, split entry is created, if you would ping me for extra info or a hq photo later I'll much appreciate that. Thanks for the clue anyway!

I'd be happy to send a higher res photo outside the forum if that would be helpful?

I've tried it with a 80Gb Intel SATAIII SSD with the SATA controller left in RAID mode in the BIOS (interestingly it says "for XP only" against the IDE mode option). There was an old Win98 installation on the disk and it worked great (after detecting the new motherboard devices).

The heatsink + fan that was supplied with it is AMD stock, but it seems like the "safety lever" makes it MUCH too tight. Despite the plate on the back of the board, it pulled the whole PCB into a dramatic curve! (so I disengaged the safety lever immediately).

Even without the safety lever, the cooler clip still puts a little bit of a curve into the board, so I'll probably take it apart and try and reduce the angles in the clip to reduce the tension?

I'm guessing this means this cooler isn't quite the right one for socket 754?

justin1985 wrote on 2023-12-16, 16:55:

I'm guessing this means this cooler isn't quite the right one for socket 754?

You should be able to use some modern AM4 coolers on Socket 754.

Not sure if they are still sold new, but I have a DeepCool Ice Edge Mini FS 2.0 on my Athlon64, and it works great.

justin1985 wrote on 2023-12-16, 16:55:

The MSI Socket 754 board has arrived, and it definitely has the VT8237R Plus southbridge! […]
Show full quote

The MSI Socket 754 board has arrived, and it definitely has the VT8237R Plus southbridge!

IMG_20231216_162930.jpg

Bruno128 wrote on 2023-12-13, 16:33:

Files located, split entry is created, if you would ping me for extra info or a hq photo later I'll much appreciate that. Thanks for the clue anyway!

I'd be happy to send a higher res photo outside the forum if that would be helpful?

I've tried it with a 80Gb Intel SATAIII SSD with the SATA controller left in RAID mode in the BIOS (interestingly it says "for XP only" against the IDE mode option). There was an old Win98 installation on the disk and it worked great (after detecting the new motherboard devices).

The heatsink + fan that was supplied with it is AMD stock, but it seems like the "safety lever" makes it MUCH too tight. Despite the plate on the back of the board, it pulled the whole PCB into a dramatic curve! (so I disengaged the safety lever immediately).

Even without the safety lever, the cooler clip still puts a little bit of a curve into the board, so I'll probably take it apart and try and reduce the angles in the clip to reduce the tension?

I'm guessing this means this cooler isn't quite the right one for socket 754?

When they went from 754/939 to AM2 onward they used a new design of back plate/CPU bracket that has four mounting screws instead of two. Because of this more rigid design, the clamp for the later AM2 heat sink has less travel (and therefore less clamping force) than the ones for 754/939. I ran into this because I wanted to use a factory copper heatpipe cooler from a 6000+ AM2 on a GIgabyte 939 board that used a CPU bracket that was held in place with plastic pins rather than screws, and it didn't clamp to the CPU tightly enough because most of the travel was used pulling the bracket tight. To make this AM2 cooler work properly on the 939 motherboard, I had to buy a CPU bracket that had a metal back plate and used screws rather than plastic push pins.

So it sounds as though you do have the correct heat sink for your system, but the clamping force is too much for the PCB; in which case you would likely be better off with a cooler meant for AM2→.

Well it seemed to be going well, until I tried adding a Creative Audigy (or an SBLive!) ...

Win98SE seemed quite happy with the SATA RAID using the latest Win98 drivers from the VIA website, and I'd installed the Radeon 9250 etc.

When I added the Audigy it picked up the "Audio Processor" and the FireWire port, but none of the other usual items installed, and the Audio Processor said it was "disabled by a Windows driver" in device manager. The firewire port also said it was not present or disabled.

I tried adding and removing it a few times, moving between slots, cleaning contacts, etc, and swapping for a (retail) SBLive! But it got to the point where Windows would hang at the boot screen whenever either Creative card is installed. (the cards worked in the VIA SocketA board as well as a 440ZX board, and other PCI cards work fine in these slots).

I've tried formatting and reinstalling several times over, but get exactly the same hang at boot screen whenever the Creative card is in the system now.

Are the Creative cards just incompatible with the K8M800 chipset?

The only other things I can think to try are switching to an IDE hard drive, or maybe trying Windows ME? (better baked-in compatibility with USB2 and SATA/RAID?)

Are the two sound cards DELL OEM cards?

If so, you may need special DELL drivers to run them.

I have a DELL OEM Sound Blaster Live which gave me similar problems. I haven't messed around with the card since, but saw somewhere that if you want it to work you need a special DELL driver for it, but can't remember the specifics.

Here's a picture of my card:

justin1985 wrote on 2023-12-17, 02:32:

Are the Creative cards just incompatible with the K8M800 chipset?

There was a known latency issue between SBLive/Audigy 1 cards and certain VIA chipsets back in the day. It was solved with Audigy 2 and ZS cards on Creative's side. I use a retail Audigy 2 (SB0240) on my K8M800 system and it works just fine. Avoid OEM versions of those cards (made by Dell, HP etc.) since they tend to be picky when it comes to drivers. Also, don't bother with the cut down variants, i.e. the various LE/SE models and such.

But it got to the point where Windows would hang at the boot screen whenever either Creative card is installed.

This can sometimes happen when there's a resource conflict. If the motherboard has an integrated sound chip, make sure that it's disabled in the BIOS. It also helps to disable any other unused on-board devices such as the serial/parallel ports and network card, as that will free up some resources.

The only other things I can think to try are switching to an IDE hard drive, or maybe trying Windows ME? (better baked-in compatibility with USB2 and SATA/RAID?)

If you don't need pure DOS, then WinME is a solid option, as long as you disable System Restore (it's buggy). I like its built-in USB storage support and the option to disable mouse acceleration. The latter helps if you want to use a modern gaming mouse on your retro rig.

In case you end up doing a clean install, be sure to get the correct VIA chipset drivers. Specifically, for the K8M800, I recommend VIA Hyperion Pro version 5.09A. If you've set the SATA controller to RAID mode, then you also need to install the RAID drivers from that pack.

Irinikus wrote on 2023-12-17, 05:01:

Are the two sound cards DELL OEM cards?

If so, you may need special DELL drivers to run them.

Thanks for the suggestion. I did try to look out for this when buying them. The Audigy (original) is SB0090 and the Live! is SB4760. It looks like these should be the real deal retail cards?

Joseph_Joestar wrote on 2023-12-17, 06:46:

This can sometimes happen when there's a resource conflict. If the motherboard has an integrated sound chip, make sure that it's disabled in the BIOS. It also helps to disable any other unused on-board devices such as the serial/parallel ports and network card, as that will free up some resources.

Practically everything is already disabled - the AC'97 audio, all the legacy ports, even the LAN and the floppy controller right now.

Joseph_Joestar wrote on 2023-12-17, 06:46:

In case you end up doing a clean install, be sure to get the correct VIA chipset drivers. Specifically, for the K8M800, I recommend VIA Hyperion Pro version 5.09A. If you've set the SATA controller to RAID mode, then you also need to install the RAID drivers from that pack.

I was using an older version of the Hyperion drivers. And the separate SATA RAID drivers from the MSI site. So I'll give this version a try.

I've done two fresh installs and get the same issue of hanging at boot screen when a Creative card is installed - before I've even had the chance to install a Creative driver!

(I only got as far as the not working Creative driver installation before I did any format and fresh install - but thinking about it, maybe I used different RAID driver version originally?)

If the same thing is happening after fresh formats and Windows installations, I guess that suggests it as an incompatibility with a driver that's already installed (i.e. one of the VIA drivers) ? Or a concrete hardware compatibility ?

Joseph_Joestar wrote on 2023-12-17, 06:46:

There was a known latency issue between SBLive/Audigy 1 cards and certain VIA chipsets back in the day. It was solved with Audigy 2 and ZS cards on Creative's side. I use a retail Audigy 2 (SB0240) on my K8M800 system and it works just fine.

Hmmm maybe another purchase might end up being the way forward then ...

I guess I was targeting game sound quality, and sound font MIDI including DOS games running inside Windows with this build (I'm keeping the 440ZX PIII system to target native DOS).

Would one of the Aureal cards be another option? I've seen them discussed re: 3D audio, but do they also do rich MIDI?