Here are some settings from my gigabyte 486vs for reference.

I have exactly the same Board . Rev 8a. Irq15 shows up as free. But VLB io card has two Channels and both activated.i mean i cannot disable ide channels with jumpers on that card. Checked all of
them.

VLB cards with multiple IDE ports but no own BIOS used to come with drivers that would enable the other port and detect the hard drives. I don't think many (if any) motherboards without integrated IDE controller have support for secondary IDE channel in BIOS by default.

ZipoBibrok wrote on 2019-09-02, 02:37:

VLB cards with multiple IDE ports but no own BIOS used to come with drivers that would enable the other port and detect the hard drives. I don't think many (if any) motherboards without integrated IDE controller have support for secondary IDE channel in BIOS by default.

I see this is an old thread, but is something ive always wanted an answer too myself.
I have indeed seen such a machine with a VL bus dual IDE multi/IO card and no on board controller, and the BIOS supported primary and secondary IDE channels on the VL bus I/O card.

It was an award BIOS too, ive never seen any AMI BIOS (well the "colour" ones as they call them) that have this feature as far as I can tell.
There would have only been a very short period in the 486 era where boards had such support too i guess.

Interestingly enough, I bought a NOS VL bus I/O card on an online auction, still in its box with a driver disk. This card has its own BIOS chip that lets you configure the drives in much the same way as an MFM controller card would, except you dont need to run debug on DOS to access the utility.
The brand is pine, and im not sure what the driver disk is needed for, but i should share an image of it here on the driver page, as it may useful to others and work with various cards.

I also have a dual IDE port ISA I/O card, which is very rare and the first one ive seen.

I might put it in my 386 system im building. Dunno how I can get the secondary channel to work though if the BIOS doesnt support the second channel.

I was told that the XTIDE ROM will work for this.
Anyone tried this? It might be worth a shot to throw a ROM chip with XTIDE burned on to it in a network card or something. I think this would be the answer if this works. One advantage is it allows you to use much larger drives too.

you can use an optical drive on the secondary channel without any need for BIOS support

if you want a HDD on secondary, use the XTIDE ROM like you said

OK thats sweet, makes things much simpler.
So handy to have the XTIDE ROM, never used to have that once!