I've had this 486 DX4 100mhz for a while. It's a EXP8049 rev. 1.1a by DATAEXPERT and supports pretty much all 486 CPUs, 64MB RAM and 512k cache. A pretty good board, but I've failed to get any CF card working nor any regular drives over 500mb. Only with the use of OnTrack I was able to use a 4gb hdd. I looked into the manual and references online and saw that someone must have swapped out the BIOS at some point. It was a generic EEPROM. I've found a picture of the board with the original BIOS, showing it actually used a AMI 486PCI ISA BIOS.

Some questions:
1. Does anyone have this exact board and the original BIOS? The manual has a Phoenix BIOS as example. I've not seen any other references with this BIOS anywhere, though.
2. Can I swap out the BIOS with any other AMI 486PCI ISA BIOS? I've seen a few similar boards with the same BIOS chip for which I could download the BIOS file.
3. Is there anything else preventing me from using CF cards or HDDs over 500gb? I know this is a limitation on much older systems but I was suprised it was a problem with this board or the current BIOS.
4. There is text on the motherboard mentioning "BEST PERFORMANCE FOR AM486 PROCESSORS". Could that be true or is it just a marketing gimmick? If it's true, how exactly?

Thanks for any help I might receive 😀