Reminds me of a board that Fabian (Amoretro) had for sale.

Anyway, this is a very interesting board because of the 486 capability. If i had one of these i would replace that 80 MHz crystal oscillator with a 100MHz one, replace those cache chips with -10ns ones i have and give it 60ns simms. With no PCI or VLB, it should have potential for a 386 DX 50 and a 486 DX 50. 😁

I just noticed, you are running your ISA bus @13.3MHz, if i'm not mistaken. 80/6=13.3 and that should explain why the Tseng is giving that good score in benches.

While some cards run fine beware that some other ISA cards (I/O cards) might struggle and have trouble with a higher ISA clock.

The frequency gets halved from 80 to 40 MHz. So it runs at 40 / 6 = 6.7 MHz. But it is set to Auto Configure, so not sure what it actually runs at 😀

I tried 40/4 and that worked fine and gave me an even better score. I don't think it's 80/4 because the cards simply wouldn't work anymore.

I have no need for more speed. I can use a 486 or Pentium for that 😀

Some tests with cache disabled:

3dbench: 8.1

Doom 20545 realticks or 3.64 fps.

BIOS tuned results:

Settings:

Or 9.17 fps.

You're right, i didn't watch closely. Now i see it says CPUCLK and not CLK2 as i was expecting, which is the case of my motherboard.

carlostex wrote:

You're right, i didn't watch closely. Now i see it says CPUCLK and not CLK2 as i was expecting, which is the case of my motherboard.

Yea, I ordered some crystal oscillators. You need 80, 66.666 and 50 to get 40, 33.333 and 25 MHz on this board.

I'm gonna try a 386DX-50 this as soon as i get a new 386 board. Not because i need more speed but because it's something unusual, and i like that kind of stuff. I'm gonna build a 486DX-50 too. 😎

http://www.ebay.com.au/itm/FX-3000-Rev-1-0-48 … 6-/200355644784

That seller had 3 boards. Two sold vor ~$100 and ~$200 each. One left 😲

Could someone provide a bios image please ?

also what is the speed of the oscillator in the middle that is zip-tied? I have the mobo but it lacks the oscillator, I'd like to test it and see if it works

keropi wrote:

also what is the speed of the oscillator in the middle that is zip-tied? I have the mobo but it lacks the oscillator, I'd like to test it and see if it works

Double the frequency of the clock speed. So for a DX40 you need a 80 MHz oscillator. Tested with 66 and 50 as well, works great.

^ yes makes sense 🤣 thanks Phil
I'll make a dump of the bios BastlerMike , will attach it later here

BastlerMike wrote:

Could someone provide a bios image please ?

I can give it a shot!

I have a flasher from eBay, would this work?

^ yes it will work, the bios is a 27C512

the mobo I have is the 486DX variant, it has a socket for a 486 cpu and soldered the VLB slot.
sadly there is no BIOS chip on mine...

I have three of these boards. Two working, one none working. The none working still has the bios chip in it, and I know its still good as I swapped the chip with the another one from a working board and the working board booted just fine.

I haven't played around with it much (been busy with all these new babies!) but looks interesting. One has a 486 Overdrive 75Mhz in it, the other two a 386DX-33. I have about a dozen or so different oscillators (25Mhz up to 80MHz), but need to understand how it works in this board. Most boards the oscillator are double the CPU MHz, so a 40MHz 386 needs an 80MHz crystal. However, on some boards it seemed that its exactly the CPU MHz. Is it just for 486 that its the exact same speeds, and the 386 is halved?

keropi wrote:

^ yes it will work, the bios is a 27C512

the mobo I have is the 486DX variant, it has a socket for a 486 cpu and soldered the VLB slot.
sadly there is no BIOS chip on mine...

According to this thread Re: Motherboard FX 30000 D Rev 1.0 (386/486 hybrid) it is not a VESA compatible slot.
My board has the 386 socket, 486 socket and local bus slot. It was manufactured in late '92. Maybe on later boards they left the slot unpopulated to circumvent confusion with the then finalized VESA specifications.

Plugging VLB cards in this slot prevents the system from powering on because of a short circuit. DO NOT use VLB cards with this mainboard !
Only special local bus cards made by Elitegroup as named in this post Re: Pre-VESA Proprietary 32-bit Local Buses? will work!

I finally found a working bios for the FX-3000 motherboard. It belongs to the Elitegroup UM486V (dated 04/26/93)
There's also a probably generic MR bios for the UMC 481 chipset available.

Thank you!