No. That motherboard contains a 169-pin Socket 1 whereas the Pentium 83MHz OverDrive requires a 237-pin Socket 3.

At best you could install an Am5x86-133MHz CPU from the likes of Kingston or Evergreen Technologies. The Am5x86 performs about as fast as a Pentium 75MHz in integer/ALU speed, but is much slower in FPU speed.

5V only board, so an Am5x86 would have to be the Kingston/Evergreen carrier upgrade, might be possible to use the Scrap Computing 3V interposer for a regular CPU

Folks have made a pod work in socket 1 by elevating the cpu using a set of socket 1 sockets inserted in the board to elevate the pins above the components around the socket.

Even when you do this the cache, bios and other incompatibilities may surface

It does work in socket 1. The extra pins are extra VCC & GND.

Another option is a DX4-100 ODP/R. The ODP is 169 pin, the ODPR is 168 pin. At 120Mhz they are similar to a Am5x86 in floating point, and similar to a POD83 in integer.

Hallo egbertjan,

I have this board, and it has the Ver 1.143K BIOS as well. I’m running an i486SX-25 on this 4386-VIO board and this works fine, so I never had the need to update the BIOS.
But you made me curious, and I will try the latest Ver 2.06K BIOS to see what is changed.

Using my hexeditor to look at the CPU support in the 2.06k BIOS, I see support for these CPUS:
80386DX, 80386SX, 80386SL, 80486SX, 80487SX, 80486DX, 80486DX2, Cx486SLC, Cx486DLC, Cx486S, Cx486S2, IBM386SLC, IBM486SLC2, and P24T (POD63/83).

A typical list for a 386/486 board from that era, but the P24T support is a nice surprise. The 1.143k BIOS didn’t have that.
With the 1.143k BIOS I did try a Cx486DX-40 once, but this didn’t work and looking at the above list, it won’t work with the 2.06k BIOS either.
Using an interposer for 3.3V, a DX4 will probably work fine, but the BIOS sees it as an 80486DX2-100.

I will report back when I have tried the 2.06k BIOS.

Groetjes, Jan

I’ve installed the Ver 2.06k BIOS on my FIC 4386-VIO and it works great!
Because the previous Ver 1.143k uses the v4.20 Award BIOS core, and the Ver 2.06k the v4.50 core, there are some nice improvements.

The initial POST screen still displays the same list of tests, but you can now simply hit the Del key, instead of Ctrl-Alt-Esc, to enter the CMOS Setup.

The 1.143k BIOS has only 2 Setup screens with a limited amount of options.

The 2.06k BIOS shows the more familiar Award BIOS CMOS Setup with a lot more menus and options. You even get an IDE HDD AUTO DETECTION menu, saving you the hassle of entering the drive’s CHS values manually. 😀

And the 2.06k BIOS has a System Configurations summary screen that the 1.143k BIOS lacks.

Unfortunately, being a 1993 BIOS, the Ver 2.06k still has the 504MB IDE HDD limit, just like the 1.143k BIOS had. So for larger drives, you need a solution like XTIDE Universal BIOS or Drive Overlay software.

Cheers, Jan

Thank you Jan, I am very happy about what you wrote about the BIOS Ver 2.06k. I would like to upgrade the BIOS on my board, but the BIOS-chip on my board is not programmable. Do you know which chip I can use? When I have the right chip I can program it with my T48. By the way, do you know the jumpersettings and which crystal oscillator I have to use when I apply the P24T? Greetz, Egbert Jan.

egbertjan wrote on 2025-09-15, 21:01:

Thank you Jan, I am very happy about what you wrote about the BIOS Ver 2.06k. I would like to upgrade the BIOS on my board, but the BIOS-chip on my board is not programmable. Do you know which chip I can use? When I have the right chip I can program it with my T48. By the way, do you know the jumpersettings and which crystal oscillator I have to use when I apply the P24T? Greetz, Egbert Jan.

Your original 64KB 28-pin DIP BIOS chip is probably a 27C512 or equivalent UV-EPROM. These chips need to be erased by UV-light, hence the quarts window on top, before you can re program them.
So it is much easier to buy a new (E)EPROM to program the updated BIOS and keep the original EPROM as backup.

For these BIOS experiments I advise to use a Winbond W27C512 EEPROM. These are compatible with 27C512 UV-EPROMs but can be electrically erased for re-programming. No hassle with UV-light anymore.
Nice that you have a T48 so you can erase and program these EEPROM chips!

For the P24T in a socket 1 board, you need to set the jumpers as for a 486DX-33 / 486DX2-66. Because you run a DX2-66 now, you can leave the jumpers and the crystal as they are.

As rmay635703 and MikeSG already indicated, the POD83 can work in a socket 1 but the challenge is how to install the CPU with the outer pin rows hanging over side of the socket. Be careful that they don’t touch any component on the motherboard.

Cheers, Jan

rmay635703 wrote on 2025-09-12, 20:48:

Folks have made a pod work in socket 1 by elevating the cpu using a set of socket 1 sockets inserted in the board to elevate the pins above the components around the socket.

Even when you do this the cache, bios and other incompatibilities may surface

Best reply. It MAY work. Level 2 cache not working at all with a pod is a common problem even on boards that DO officially support it, so don't assume that the string in the bios means much. POD specs were released much before the actual CPU and as a result mileage may vary.

The few I've played with were subjectively underwhelming even when overclocked to 100mhz, I'd probably prefer just a regular 486 at 120 mhz or more.

I am looking for the Winbond W27C512 eeprom chip on the internet. I found a lot of them, they are mainly W27C512-45 or W27C512-45Z. Does anyone know the difference between those two. Can I use both as a BIOS-chip on my 4386-VIO board?

I've used the W27C512-45Z on a 386 motherboard without problems. Don't think there's a difference between the Z/non Z versions.

MikeSG wrote on Yesterday, 11:41:

I've used the W27C512-45Z on a 386 motherboard without problems. Don't think there's a difference between the Z/non Z versions.

I agree.
According the W27C512 datasheet, the “Z” indicates a Lead free package, and these versions are functionally identical to non-Z versions.

The original EPROM on my 4386-VIO is a 120ns type. So you don’t need the fastest 45ns EEPROM, any 70, 90, and 120ns version will do fine as well.
Be sure you don't order a W27C512P version, these "P" EEPROMs come in a 32-pin PLCC package.

Jan

Thank you Jan, you are very helpfull. I just bought the chip on Ebay. I will let you know wether or not it will work in a couple of days.

Egbert Jan

bertrammatrix wrote on Yesterday, 04:29:

rmay635703 wrote on 2025-09-12, 20:48:

Folks have made a pod work in socket 1 by elevating the cpu using a set of socket 1 sockets inserted in the board to elevate the pins above the components around the socket.

Even when you do this the cache, bios and other incompatibilities may surface

Best reply. It MAY work. Level 2 cache not working at all with a pod is a common problem even on boards that DO officially support it, so don't assume that the string in the bios means much. POD specs were released much before the actual CPU and as a result mileage may vary.

The few I've played with were subjectively underwhelming even when overclocked to 100mhz, I'd probably prefer just a regular 486 at 120 mhz or more.

Hi bertammatrix,

You are right of course, it MAY work. But it will be interesting to see if egbertjan can get this socket 3 CPU running on his socket 1 board.

The then unconnected outer pin rows of the POD83 are extra Vss and Vdd pins, and also the signal pins for L1 cache Write-Back mode are located there. The VIA chipset on this board doesn’t support L1 cache WB and with the POD83’s outer pin rows unconnected, the CPU will run in standard L1 Write-Through mode and doesn’t use any of these unconnected signal pins.
So I’m hopeful it will work. I will keep my fingers crossed. 😉

Apart from the correct P24T string, I also looked at the underlying software in the 2.06k BIOS, and it correctly supports the POD83 detection and handling, so the BIOS is ready for it.

Cheers, Jan