I would start with replacing the Fujitsu first. The MPG and MPF series are known to fail.
https://www.theregister.com/on-prem/2002/11/0 … ive-hdds/569760

Connor 3044, Seagate 351 A/X, type 17, done 🤣 Of course some picky buggers want more than 40Mb, I ask you. 😉

Assuming the PC has ISA slots, it'd probably just be easier to stick in an XT-IDE card (or a network card with an XT-IDE boot ROM) and then you can use whatever IDE or SATA drives that you like, or even CF cards of any size. Drive compatibility is much higher when you haven't got to rely on the PC's BIOS to set the config.

PTherapist wrote on 2026-10-14, 14:56:

Assuming the PC has ISA slots

Thank you and this is not really possible as the system only has one ISA slot which I need to use for the network card. More slots are possible with a riser, but I don't have one. I need to have a network connection as I need to be able to do MSVC 6 remote debugging.

Looking at https://theretroweb.com/motherboards/s/dec-ve … 86-433-ver.-1.0 the upper slot is the ISA slot that I use for the network card and the lower one is for the riser that I don't have. I keep wondering if I could just plug an ISA card into the lower slot, but suspect if I did something very bad may happen.

The "Personality" module slot is ISA, they just didn't like calling it ISA because in slimline case models it did not support full ISA height or length. So standard ISA riser will fit in there. Or just single ISA card use. Only thing to watch is the alignment of cards, if they were a bit worn, rounded, at the ends of the slot and relied on notch to center them on contacts, then you might be able to plug them in misaligned and potentially get a short.

Straight from horses mouth info, page 42 https://theretroweb.com/motherboard/manual/a0 … 92528340680.pdf

BitWrangler wrote on 2026-10-14, 16:32:

Straight from horses mouth info, page 42 https://theretroweb.com/motherboard/manual/a0 … 92528340680.pdf

No, the riser slot is J24 and the ISA slot is J26

looking at the riser its wired 1:1, at least on one side. You can verify buzzing pins 1 to 1 between j24 and j26

PcBytes wrote on 2026-10-13, 23:28:

I would start with replacing the Fujitsu first. The MPG and MPF series are known to fail.

I did some more testing and disks that work with my ASUS P6T SE don't work with the Venturis so I feel the disk controller has died.

The Venturis did what I needed since I installed NT4 on 2023-03-28 @ 16:19:40, but now feel I would like an i486 system with PCI, I require:

1. PS/2 Mouse
2. 4 SIMM slots with support for at least 4 x 32MB of FPM RAM
3. At least 3 PCI slots
4. Support for 25 + 33 + 40 + 50 MHz bus clocks
5. Support for PCI clock as 1/2 (50->25) bus clock

and would like:

1. PS/2 Keyboard
2. Support for write-back L1 cache
3. Support for EDO SIMMs, ideally 4 x 128MB
4. Inbuilt support for 3.3 + 3.45 volt CPUs
5. Inbuilt support for PATA to SATA adapters so I can use a SATA SSD
6. Support for PCI clock as 2/3 (50->33) + 5/6 (40->33) bus clock
7. ATX form factor/power (I suspect only in my dreams)

Do such motherboards exist, which models are reliable/recommended please? Links to https://theretroweb.com/ would be ideal, I have tried Google.

Is https://theretroweb.com/motherboards/s/soyo-sy-4saw a reliable board and how do the SY-4SAW2 and SY-4SAW5 variants differ please?

I decommissioned the Venturis I had about 20 years ago because the PSU got ripple so bad it made the needle of an analog meter buzz. On other systems I have had weird HDD issues with noisy PSU. It might therefore be an idea to jumper the system with a standard PSU used externally (Because AFAICR the Venturis PSU was a funny shape) and see if the drives behave again. Nowadays there are more options with mini PSUs that could be put inside the old shell, but I trashed mine back then due to low to zero value of system at the time and no economic way forward with PSU.

BitWrangler wrote on Yesterday, 15:45:

I decommissioned the Venturis I had about 20 years ago because the PSU got ripple so bad it made the needle of an analog meter buzz.

Thank you for the thought, but I don't use a Venturis PSU, I just bought the board and have always used a Thermaltake Smart DPS G 750W or similar. I use the same PSUs for many of my test systems.

red-ray wrote on Yesterday, 07:37:

Is https://theretroweb.com/motherboards/s/soyo-sy-4saw a reliable board and how do the SY-4SAW2 and SY-4SAW5 variants differ please?

The 4SAW is a good board, but the barrel battery always leaks and needs to be taken care of. A coin cell holder can be easily installed, but a component needs to be removed to prevent charging the battery.
4SAW2 means that it originally came with 256 KB of cache, and 4SAW5 is for 512 KB. A PS/2 mouse header can be modded. There is no EDO support in my experience.

Realistically, the only way you are going to get out-of-the-box PS/2 ports on a 486 is with a prebuilt PC (like the DEC Venturis).

An alternative to the Soyo would be the ASUS PVI-486SP3: https://theretroweb.com/motherboards/s/asus-pvi-486sp3
It has a coin cell (no leaks) and a PS/2 mouse header. There is also no EDO support. The prices for these two boards are typically very high.

watson wrote on Today, 16:09:

There is no EDO support in my experience.

Thank you for the information, I found https://www.youtube.com/watch?v=eUaoXPgnZvo&t=189s which shows how to add the PS/2 mouse and change to a CR2032.

It seems that for EDO support you need a later revision on the SiS 85C486, see Re: Soyo SY-4SAW2 Rev WA3

What revision does your board have please? Attached is an image of the chip to check. I just checked the datasheet and wonder, is FPM/EDO type DRAM detection control enabled on your board

I was gonna suggest a Shuttle HOT-433, but they also lack EDO, have a PS/2 header though. Same problem of $$$ generally.

Late UMC chipsets support EDO but finding one on a "reputable" board that also has PS/2 header is a problem. However there's the KBC mouse hacks to play with.

Some while back I encountered an otherwise AT board with a double PS/2 socket in place of the 5 pin DIN but can't for the life of me remember what it was now.

BitWrangler wrote on Today, 17:00:

I was gonna suggest a Shuttle HOT-433, but they also lack EDO, have a PS/2 header though. Same problem of $$$ generally.

Thank you for the thought, but I only have 32 MB FPM SIMMs, I have 64 + 128 MB EDO SIMMs so with the Soyo I can have have 256 MB.
Given the number of Socket 3 CPUs I can't currently use I will just have to spend the £££.

The DEC Venturis Pentium 560 & 575 look like drop-in replacements, but they need a riser card to have PCI slots. And they're pentiums.

https://theretroweb.com/motherboards/s/dec-ve … ris-pentium-560
https://theretroweb.com/motherboards/s/dec-ve … ris-pentium-575

MikeSG wrote on Today, 17:57:

The DEC Venturis Pentium 560 & 575 look like drop-in replacements, but they need a riser card to have PCI slots. And they're pentiums.

Yes 😕, but I need a Socket 3 motherboard

red-ray wrote on Today, 16:43:

What revision does your board have please? Attached is an image of the chip to check. I just checked the datasheet and wonder, is FPM/EDO type DRAM detection control enabled on your board

My board has northbridge revision NV, so that's why there is no EDO support.

If you really need EDO, you could take a look at boards with the ALi M1489/87 (FinALi) chipset, it should support up to 128 MB according to the datasheet.
On the other hand, it you go with the UMC UM8881F, only revisions starting with E (EYA/EYS/EYT) will support EDO: Information wanted for UMC UM8881F sub-revisions