boxpressed wrote on 2020-05-22, 17:24:

This is the motherboard I use for bench testing most of my ISA, VLB, and PCI cards under DOS and Windows 3.1. […]
Show full quote

This is the motherboard I use for bench testing most of my ISA, VLB, and PCI cards under DOS and Windows 3.1.

http://www.elhvb.com/mobokive/archive/epox/ma … uals/486spm.pdf

I'm really pleased with this motherboard and its versatility, but I've always been a little confused by the CPU selection jumpers. Here's the part of the manual that addresses the matter.

486spmcpu.JPG

Right now, I'm using an Intel 486SX2-66, and there are two "Resister Packs" (like a long, skinny 10-pin thing), one on S4 and one on S6. It works perfectly. However, I want to test some AMD 5x86 and Cyrix 5x86 CPUs, and I'm not sure what the difference is between S4 and S7 when it comes to the AMD 5x86. Or for the P24D I'm running now, for that matter, which seems to be fine with S4 and S6. I assume that both packs have to be inserted.

Would you use S4 or S7 for an AMD 5x86-P75? Or any idea what the logic is behind the combo of the two packs?

Here are the other jumper settings that have to do with the CPU.

486spmcpu2.JPG
486spmcpu3.JPG

I found this board without its EPROM chip. Is there anyway you can share the bios?
I haven't been able to find it online.

Aublak wrote on 2020-09-24, 15:59:

boxpressed wrote on 2020-05-22, 17:24:

This is the motherboard I use for bench testing most of my ISA, VLB, and PCI cards under DOS and Windows 3.1. […]
Show full quote

This is the motherboard I use for bench testing most of my ISA, VLB, and PCI cards under DOS and Windows 3.1.

http://www.elhvb.com/mobokive/archive/epox/ma … uals/486spm.pdf

I'm really pleased with this motherboard and its versatility, but I've always been a little confused by the CPU selection jumpers. Here's the part of the manual that addresses the matter.

486spmcpu.JPG

Right now, I'm using an Intel 486SX2-66, and there are two "Resister Packs" (like a long, skinny 10-pin thing), one on S4 and one on S6. It works perfectly. However, I want to test some AMD 5x86 and Cyrix 5x86 CPUs, and I'm not sure what the difference is between S4 and S7 when it comes to the AMD 5x86. Or for the P24D I'm running now, for that matter, which seems to be fine with S4 and S6. I assume that both packs have to be inserted.

Would you use S4 or S7 for an AMD 5x86-P75? Or any idea what the logic is behind the combo of the two packs?

Here are the other jumper settings that have to do with the CPU.

486spmcpu2.JPG
486spmcpu3.JPG

I found this board without its EPROM chip. Is there anyway you can share the bios?
I haven't been able to find it online.

My saddest event in years was my crappy PSU blowing up and taking this board with it earlier this year. If anyone has a BIOS, I would also be interested!

boxpressed wrote on 2020-09-24, 17:31:

Aublak wrote on 2020-09-24, 15:59:

boxpressed wrote on 2020-05-22, 17:24:

This is the motherboard I use for bench testing most of my ISA, VLB, and PCI cards under DOS and Windows 3.1. […]
Show full quote

This is the motherboard I use for bench testing most of my ISA, VLB, and PCI cards under DOS and Windows 3.1.

http://www.elhvb.com/mobokive/archive/epox/ma … uals/486spm.pdf

I'm really pleased with this motherboard and its versatility, but I've always been a little confused by the CPU selection jumpers. Here's the part of the manual that addresses the matter.

486spmcpu.JPG

Right now, I'm using an Intel 486SX2-66, and there are two "Resister Packs" (like a long, skinny 10-pin thing), one on S4 and one on S6. It works perfectly. However, I want to test some AMD 5x86 and Cyrix 5x86 CPUs, and I'm not sure what the difference is between S4 and S7 when it comes to the AMD 5x86. Or for the P24D I'm running now, for that matter, which seems to be fine with S4 and S6. I assume that both packs have to be inserted.

Would you use S4 or S7 for an AMD 5x86-P75? Or any idea what the logic is behind the combo of the two packs?

Here are the other jumper settings that have to do with the CPU.

486spmcpu2.JPG
486spmcpu3.JPG

I found this board without its EPROM chip. Is there anyway you can share the bios?
I haven't been able to find it online.

My saddest event in years was my crappy PSU blowing up and taking this board with it earlier this year. If anyone has a BIOS, I would also be interested!

Sad. I'll let you know of any updates then.

I started repair this mobo (damaged socket) and can share with dump

Good luck. I hope everything goes swimmingly.

I have added the bios here : https://www.ultimateretro.net/en/motherboards/6241 (thanks aublak for notifying me).

By the way could one of you help to add a photo of that board to ultimateretro ? 😉

I didn't fix this mobo and made photos for sale purposes.
https://drive.google.com/drive/folders/1Ur2cY … -92?usp=sharing

Thank you! They have been added to the page.

mt777 wrote on 2021-12-10, 22:33:

I didn't fix this mobo and made photos for sale purposes.
https://drive.google.com/drive/folders/1Ur2cY … -92?usp=sharing

It's unfortunate that you couldn't repair it.

I have a question. What Eprom does the mobo use? I have only one blank AM27C010 but I don't want to waste it to find out.

It doesn't matter as long is compatible with 010 pinout.
So you can use W27c010, 29c010 or eprom like m27c010 (which is also eraseable).

cool thanks.

Merry Christmas btw.

I've been away from Vogons for a while and just saw these updates. I'd like to try a new BIOS on my beloved board. Is there a service where I can buy an already flashed EPROM from someone?

I have a programmer (or three 😀 ) and can write EPROMs. I don't have this particular type of EPROM chip though. If you send me one, I'll program it for you. It doesn't have to be blank, I can erase EPROMs too.

stamasd wrote on 2022-01-25, 14:16:

I have a programmer (or three 😀 ) and can write EPROMs. I don't have this particular type of EPROM chip though. If you send me one, I'll program it for you. It doesn't have to be blank, I can erase EPROMs too.

Thank you! I will try to source one and will get back to you.

No problem. Send me a private message when you do.

Also, many old boards take EEPROMs too, and those are easier to deal with (erasing takes a few seconds in a programmer rather than 15 minutes under an UV lamp). I have successfully used EEPROM chips on boards as old as IBM 5160 without a problem. I only have EPROMs and EEPROMs up to 64kx8 though, none 128kx8.