A quick search took me here: https://www.dell.com/support/home/en-us/drive … ode=dimension-t
Also: not sure you can run a 66mhz bus CPU (233Mhz or 266Mhz) according to the Dell manual, lists only 100Mhz bus cpu's. The SE440BX-3 Intel Tech Prod Spec says 66Mhz or 100Mhz bus....

Horun wrote on 2022-12-11, 15:33:

A quick search took me here: https://www.dell.com/support/home/en-us/drive … ode=dimension-t
Also: not sure you can run a 66mhz bus CPU (233Mhz or 266Mhz) according to the Dell manual, lists only 100Mhz bus cpu's. The SE440BX-3 Intel Tech Prod Spec says 66Mhz or 100Mhz bus....

Nice find! That does appear to be the same bios in the 2nd link but I would feel more comfortable using the one you found. Thank you! Also you are 100% correct. The Pentium 2 266Mhz cpu I picked up does have a fsb of 66Mhz. Looks like the slowest p2 with 100mhz fsb is the 350. I might try that. No idea if it will work better in dos but might be worth a try.

k9cj5 wrote on 2022-12-11, 20:13:

Horun wrote on 2022-12-11, 15:33:

A quick search took me here: https://www.dell.com/support/home/en-us/drive … ode=dimension-t
Also: not sure you can run a 66mhz bus CPU (233Mhz or 266Mhz) according to the Dell manual, lists only 100Mhz bus cpu's. The SE440BX-3 Intel Tech Prod Spec says 66Mhz or 100Mhz bus....

Nice find! That does appear to be the same bios in the 2nd link but I would feel more comfortable using the one you found. Thank you! Also you are 100% correct. The Pentium 2 266Mhz cpu I picked up does have a fsb of 66Mhz. Looks like the slowest p2 with 100mhz fsb is the 350. I might try that. No idea of it will work better in dos but might be worth a try.

The file @Horun linked is the one I used to update the BIOS on my board - works fine with a 1GHz P3

I'm going to guess the SE440BX-3 behaves like the SE440BX-2. If this is the case, look at the bottom right corner-edge of the board next to the onboard speaker. There's a jumper there. You need to set that properly to install a Pentium II, first. I think it's set 1-2; move it to 2-3 (or vice versa). Install the Pentium II, power on, and a menu pops up (or it may be available in the BIOS once you enter it; I can't remember exactly as it's been a while). Select the 233MHz option. Move the jumper back to 1-2 when finished and powered down. Powerup after the jumper is back to the default position, and you should be good to go from this point forward.

Good to know ! Here is the extracted pages from 440BX-2

Meatball wrote on 2022-12-11, 21:15:

I'm going to guess the SE440BX-3 behaves like the SE440BX-2. If this is the case, look at the bottom right corner-edge of the board next to the onboard speaker. There's a jumper there. You need to set that properly to install a Pentium II, first. I think it's set 1-2; move it to 2-3 (or vice versa). Install the Pentium II, power on, and a menu pops up (or it may be available in the BIOS once you enter it; I can't remember exactly as it's been a while). Select the 233MHz option. Move the jumper back to 1-2 when finished and powered down. Powerup after the jumper is back to the default position, and you should be good to go from this point forward.

I dont know if I tried this or not when I installed the p2 266 the first time. Do think its worth tryin again? Or will this board only work with 100MHZ fsb cpus's? Thanks again for everyone's responses.

PC Hoarder Patrol wrote on 2022-12-11, 20:37:

k9cj5 wrote on 2022-12-11, 20:13:

Horun wrote on 2022-12-11, 15:33:

A quick search took me here: https://www.dell.com/support/home/en-us/drive … ode=dimension-t
Also: not sure you can run a 66mhz bus CPU (233Mhz or 266Mhz) according to the Dell manual, lists only 100Mhz bus cpu's. The SE440BX-3 Intel Tech Prod Spec says 66Mhz or 100Mhz bus....

Nice find! That does appear to be the same bios in the 2nd link but I would feel more comfortable using the one you found. Thank you! Also you are 100% correct. The Pentium 2 266Mhz cpu I picked up does have a fsb of 66Mhz. Looks like the slowest p2 with 100mhz fsb is the 350. I might try that. No idea of it will work better in dos but might be worth a try.

The file @Horun linked is the one I used to update the BIOS on my board - works fine with a 1GHz P3

Dell SE440BX-3.jpg

[/quote]
The file @Horun linked is the one I used to update the BIOS on my board - works fine with a 1GHz P3
[/quote]

The E139761 number near the cmos battery matches mine and the layout is the same. So its a SE440BX-3. Good to know. Also thanks for letting me know that bios also worked for you. Question, did you get your on board audio to work? The onboard Yamaha YMF724F-V seems like it would pair nicely with native opl3 support but I cant seem to get mine going. Wondering if you had any luck with yours.

k9cj5 wrote on 2022-12-12, 03:01:

Meatball wrote on 2022-12-11, 21:15:

I'm going to guess the SE440BX-3 behaves like the SE440BX-2. If this is the case, look at the bottom right corner-edge of the board next to the onboard speaker. There's a jumper there. You need to set that properly to install a Pentium II, first. I think it's set 1-2; move it to 2-3 (or vice versa). Install the Pentium II, power on, and a menu pops up (or it may be available in the BIOS once you enter it; I can't remember exactly as it's been a while). Select the 233MHz option. Move the jumper back to 1-2 when finished and powered down. Powerup after the jumper is back to the default position, and you should be good to go from this point forward.

I dont know if I tried this or not when I installed the p2 266 the first time. Do think its worth tryin again? Or will this board only work with 100MHZ fsb cpus's? Thanks again for everyone's responses.

That depends how badly you want to run with a Pentium II. It doesn't hurt anything and takes a few minutes, otherwise.

Check the entire set of drivers for your Dimension XPS T___ series as the list contains hardware that might match your computer; this would reduce the chance of misidentifying your model.

I found driver for Number Nine Motion 771 (S3 Vision968) of 1995 and BIOS of 1996 for my Dimension XPS P___c MDT (bought in 1995 and currently the oldest functioning computer in my collection) on their website; I have to give Dell a thumb up for archiving so many drivers for their legacy products. The only other company maintaining a similar database is Lenovo / IBM.

k9cj5 wrote on 2022-12-12, 03:01:

Meatball wrote on 2022-12-11, 21:15:

I'm going to guess the SE440BX-3 behaves like the SE440BX-2. If this is the case, look at the bottom right corner-edge of the board next to the onboard speaker. There's a jumper there. You need to set that properly to install a Pentium II, first. I think it's set 1-2; move it to 2-3 (or vice versa). Install the Pentium II, power on, and a menu pops up (or it may be available in the BIOS once you enter it; I can't remember exactly as it's been a while). Select the 233MHz option. Move the jumper back to 1-2 when finished and powered down. Powerup after the jumper is back to the default position, and you should be good to go from this point forward.

I dont know if I tried this or not when I installed the p2 266 the first time. Do think its worth tryin again? Or will this board only work with 100MHZ fsb cpus's? Thanks again for everyone's responses.

Yes I would try it, follow the instructions in the 440BX-2 pdf . Do not flash the BIOS before trying it. Some times they remove older CPU support to add newer.

k9cj5 wrote on 2022-12-12, 03:03:

PC Hoarder Patrol wrote on 2022-12-11, 20:37:

The file @Horun linked is the one I used to update the BIOS on my board - works fine with a 1GHz P3
Dell SE440BX-3.jpg

The file @Horun linked is the one I used to update the BIOS on my board - works fine with a 1GHz P3

The E139761 number near the cmos battery matches mine and the layout is the same. So its a SE440BX-3. Good to know. Also thanks for letting me know that bios also worked for you. Question, did you get your on board audio to work? The onboard Yamaha YMF724F-V seems like it would pair nicely with native opl3 support but I cant seem to get mine going. Wondering if you had any luck with yours.

Others here also have had trouble with the on-board audio. Seems the YMF724F-V is more for "add-on" PCI cards than built-in. Check this topic:
SE440BX-3 YMF724F-V 98SE driver refuses to install
I did not see the Yamaha driver in the list from Dell for your model. Not sure why..
https://www.dell.com/support/home/en-us/produ … nsion-t/drivers

dormcat wrote on 2022-12-12, 03:50:

Check the entire set of drivers for your Dimension XPS T___ series as the list contains hardware that might match your computer; this would reduce the chance of misidentifying your model.

I found driver for Number Nine Motion 771 (S3 Vision968) of 1995 and BIOS of 1996 for my Dimension XPS P___c MDT (bought in 1995 and currently the oldest functioning computer in my collection) on their website; I have to give Dell a thumb up for archiving so many drivers for their legacy products. The only other company maintaining a similar database is Lenovo / IBM.

Agree !! They still have drivers/stuff for my Vostro 1500 laptop last time I checked.