I tried the CF card back on my previous motherboard and voila, it works! It still doesn't want to work on my new motherboard. Is it possible the CPU is causing the problem (The previous board has an Intel DX2-66 whereas the upgraded board has an am5x86-133)?

Edit: Is phoenixbios known for having these issues compared to AMIbios?

Looking more on the page for my upgrade motherboard, it missing documentation for several different jumpers, and I even found some of the "miscellaneous" jumpers were in the wrong position from what the manual said it should be.

Edit: I activated VL-Bus wait states, but now I can't even detect the drive. This controller is the only one I have, but it is so flimsy. The board is also ever-so-slightly bent, making me wonder if it isn't making good contact (the other board I have isn't bent).

I had major problems with CF card using the AMIBIOS in my 486 - would see them but never could get them to boot etc.
I burnt an EEPROM with XTIDE bios and put it into a LAN card and that solved it. I used a TommyPROM breadboard EEPROM burner https://github.com/TomNisbet/TommyPROM

Would be worth trying your CF card in a virtual machine and see if you can install DOS on it and then boot the virtual machine fom the CF card.
If that works, then the card is probably ok and it is your 486 bios being a pain.

I spent ages figuring that out! Could only boot from one specific CF card prior (though was making all my installs in a VM as I dont have a floppy drive)

I found virtualbox in windows didnt really like accessing the CF card as a physical disk but worked really well on lubutu linux
https://www.serverwatch.com/server-tutorials/ … tualbox-vm.html

TelamonLivesOn wrote on 2020-07-07, 18:47:

Looking more on the page for my upgrade motherboard, it missing documentation for several different jumpers, and I even found some of the "miscellaneous" jumpers were in the wrong position from what the manual said it should be.

Edit: I activated VL-Bus wait states, but now I can't even detect the drive. This controller is the only one I have, but it is so flimsy. The board is also ever-so-slightly bent, making me wonder if it isn't making good contact (the other board I have isn't bent).

squelch41 wrote on 2020-07-07, 20:34:

I had major problems with CF card using the AMIBIOS in my 486 - would see them but never could get them to boot etc. I burnt an […]
Show full quote

I had major problems with CF card using the AMIBIOS in my 486 - would see them but never could get them to boot etc.
I burnt an EEPROM with XTIDE bios and put it into a LAN card and that solved it. I used a TommyPROM breadboard EEPROM burner https://github.com/TomNisbet/TommyPROM

Would be worth trying your CF card in a virtual machine and see if you can install DOS on it and then boot the virtual machine fom the CF card.
If that works, then the card is probably ok and it is your 486 bios being a pain.

I spent ages figuring that out! Could only boot from one specific CF card prior (though was making all my installs in a VM as I dont have a floppy drive)

I found virtualbox in windows didnt really like accessing the CF card as a physical disk but worked really well on lubutu linux
https://www.serverwatch.com/server-tutorials/ … tualbox-vm.html

TelamonLivesOn wrote on 2020-07-07, 18:47:

Looking more on the page for my upgrade motherboard, it missing documentation for several different jumpers, and I even found some of the "miscellaneous" jumpers were in the wrong position from what the manual said it should be.

Edit: I activated VL-Bus wait states, but now I can't even detect the drive. This controller is the only one I have, but it is so flimsy. The board is also ever-so-slightly bent, making me wonder if it isn't making good contact (the other board I have isn't bent).

Thankfully, I have an NIC card I can use, I might try this. I did test the CF card in a different motherboard, which worked, but I need to use this motherboard for hardware compatibility. It am also thinking that I need to carefully flatten the board (it is slightly bent from pushing VLB cards in it).

Thankfully, I have an NIC card I can use, I might try this. I did test the CF card in a different motherboard, which worked, but I need to use this motherboard for hardware compatibility. It am also thinking that I need to carefully flatten the board (it is slightly bent from pushing VLB cards in it).

You may well be able to flash XTIDE eeprom in your NIC too but if not, the tommyprom works well

Long shots:
Could you try to create partitions with LBA turned off? (Normal mode) if so, you could get full capacity with some drive overlay software.
I have a 486 too that does support LBA. With one controller, even 8GB CF is working perfectly. On another controller it refuse with LBA turned on, even a normal 420MB hard drive. Turning LBA off solvers the problem for this card.
On the other hand, one of my VLB controllers has its own bios extension with LBA support.
Maybe some XTIDE might help on your case?

Some even longer shots:
Is there a boot sector anti virus in your bios? And returned off?
Are your install disks scanned by antivirus software recently?
Any other boot disk available to partition the CF?

Myself I have a 64MB universal CF card for use in any computer to benchmark it. I created the partitions on a 386 computer, obviously without LBA support. When used in any LBA supported system the drive fails to boot. When I set the control in bios from auto to normal, it boots just fine.
A bit the other way around, just to illustrate the weird differences between controllers.

I swear this PC is cursed. It now won't recognize ANY IDE devices (even real hdds less than 500mb). I am starting to think that the motherboard needs a reflow or something. How could the bios be so picky with even real hdds set to the correct settings. It keeps saying "Failure Fixed Disk 0". Switching the slots of the video and controller cards doesn't seem to help (even though this helped a few days ago). The only thing I have ever physically changed on this is adding a pin header to the board where one was missing (this is prior to inserting cards and misc setup). I am absolutely stumped: is the bios bad, is the controller bad, is the motherboard bad, is the chipset bad, have I damaged something, is there a bad solder joint and/or bad card connection???

WIth it can't even recognize normal HDD, I would say it's just a disk controller card problem. Best way to verify this is to test it out with another controller, or test this controller on another board. Have you tried cleaning the edge connectors of the card with an eraser to remove any oxidation? Would also check the jumpers on the card that selects the IDE transfer rate, and the jumpers on the motherboard that set the VLB wait state and clock (<=33MHz or >33MHz).

Unfortunately, I have no clue what controller card I have, leaving me clueless on the jumper settings. The interesting thing is that the floppy controller part of the card work and used to be able to detect a hard drive (Couldn't partition though), but now won't detect anything. I have verified that the controller works on another motherboard, but that system has a different bios and different jumpers set. I do, however happen to have a scsi controller and a scsi hdd, but the hdd is 68-pin whereas the controller is 50-pin. I will likely have to get an adapter for this, but I would love to find out what VLB controller card I have. I have the exact model as the one shown here: My new old crusty 486 system If you know what controller this is: could you send me a link (I cannot find much on it).

Is your motherboard the same too? If so then I would check the VLB wait state (JP34) and bus speed (JP35). Try setting it to <=33MHz (JP35 open) and 1 wait state (JP34 closed) and see if things improved. As for the super i/o controller you can try searching it here.

This card looks quite similar to the VLB controller shown in the picture. The right side looks the same so probably the jumpers too. The left side is different as it has 2 IDE channels. But if you card has the Promise PDC20230 then jumpers would be similar too.

Does your bios have a write-back caching option you can disable?

Just a few long shots:

could you clock down your CPU to 20 or 25 MHz bus speed and disable all cache? If that works, it is probably the VLBus that can't handle it. Wait states would be your friend.

Do you have a cheap Triedent or oak ISA video card to temporary swap? Those would not interfere with VLB card and maybe solve the HDD issues, helping to sort things out. VLB card may interfere sometimes, making solutions hard to discover...

The only other things I can think of are more obvious or radical:
- clean it again, I tend to use some piece of cloth that is used to clean glasses.
- find yourself another controller, ISA or VLB to test it with. That should sort out of its the bios failing on you.

I have managed to enable the wait states for the VL-Bus and keep the its clock speed normal, but this didn't seem to change anything (actually, it made the drive not detect at all after that; I tried to undo that but it still wouldn't detect). I do see the on pin on the ide connector is a little crooked (the cable still fits, but the connection may be bad). However, I doubt that it would prevent it from failing detection of the drive in the bios. Also, the chipset and cpu are said to support write-back cache, but there is no option in the bios to enable/disable for this. I do happen to have some isa-only video cards, but the newest I have is an EGA card (I think my monitor can support it). I will also try to disable all cache and see if that helps, since slower speed may help. As for trying any other ide controllers, the only one I have is the one, but I do have an isa SCSI controller as mentioned in an earlier reply, but it will need an adapter for my 68-pin SCSI HDD. I will post updates soon.

Edit: Adding wait states does not change anything, I will likely try a different video card next

Edit2: Has anyone here been successful with using a network drive for booting?

Ok, it appears that it is not an overload of the VL-Bus, since I am using an EGA ISA card for temporary video (The bios surprisingly supports it) and the only other card is the VLB controller (I made sure to try the controller card in every available VLB slot). It would appear the bios/motherboard is the cuplrit here, the question is where this fault is occuring and why.

Indeed it could be the motherboard/bios.
Until you test it with another controller you can't exclude that.
It also could be the controller card failing, which can be excluded by testing in another computer.

Have you got a floppy loaded with Checkit or some other diagnostics software, just to check if the IRQs for hard disk controllers are still being used?

waterbeesje wrote on 2020-07-10, 17:11:

Indeed it could be the motherboard/bios. Until you test it with another controller you can't exclude that. It also could be the […]
Show full quote

Indeed it could be the motherboard/bios.
Until you test it with another controller you can't exclude that.
It also could be the controller card failing, which can be excluded by testing in another computer.

Have you got a floppy loaded with Checkit or some other diagnostics software, just to check if the IRQs for hard disk controllers are still being used?

I have verified that the controller works on another motherboard (both floppy and ide), but I think I will try check-it. Hopefully something good will come of it. I post an update on the results.

Yeah, I kind of expected it to not work. I think I will wait to buy a socket 7 motherboard, which will hopefully work better for my build. Thank you so very much for all your help.

Socket 7 stuff definitely is easier to set up and usually can handle any DOS program you throw at it... Except some known games, that would have struggled with the 486 as well.

waterbeesje wrote on 2020-07-10, 20:56:

Socket 7 stuff definitely is easier to set up and usually can handle any DOS program you throw at it... Except some known games, that would have struggled with the 486 as well.

Thankfully, I happen to have a socket 7 cpu on hand (Pentium MMX), though I will likely try to go under 200mhz. I will, however need a socket 7 motherboard and pci video card to make use of it. I am sure I will find it all in the next few months. Also, I didn't even realize that I have an AMD K6-2!!! Isn't that one of the best Socket 7 CPU's?