LBA translation isn't an issue for DOS software, with some exceptions like 32-bit disk access.

The maximum translated CHS geometry that can be accessed via DOS and Win95a via Int 13h is 1024/255/63 which is 8.4GB. To go beyond that, a new interface had to be standardized (Int 13h Extensions), and your BIOS doesn't have it.

The good news is, on my own Pentium systems with Award BIOS of that era, you can either use an enormous drive (1TB SATA HDD with SATA-IDE converter even on one system of mine) and just use it as 8.4GB, leaving the rest of the space inaccessible, or install overlay software like EZDrive or OnTrack to access the rest.

You can also look for and install a BIOS update. But some Award BIOSes have a bug where they lock up if the disk is over 32GB, you can't just ignore the rest of the space. Yours is so old it's immune to that bug but has the 8.4GB limit.

Are you sure a 5.25" HDD will physically fit?

What about Seatools? Can't it be used to shrink the drive to the CHS limits and make the BIOS happy? This way any HDD from last decade can be used, and these are dirt cheap if not free in local market places...

Yup, under the external 5.25" position where the big FDD is, is one internal 5.25" position, where I could add the drive.

Limiting space of such drive feels like wasting the drive, but could be good for testing ig. How is it being done? Must the drive support it through some jumper configuration?
I plan to install overlay software, but I do need to install it on disk that the bios can properly detect and read from, thus enabling access to other, bigger drives, right?

Updated BIOS seems like the best option if it could overcome the hdd addressing limits, ideally without the >32GB bug, but first I need to get more info about the board, which i believe will be doable using some sw as hwinfo, thus I need to make this thing boot anyhow.

PS: The SeaTools sounds interesting too, I will look at it.

ArrayON_56 wrote on 2025-09-15, 22:15:

- Motherboard manufacturer or model is unclear

Full Yes INTEL 82430FX on Intel 430FX chipset.
https://theretroweb.com/motherboards/s/full-y … s-intel-82430fx

Re the hard drives not been detected properly, my FIC PPro board had similar issues using an 80pin IDE cable.
Swapped this for a 40Pin cable and immediately not only were hard drives were detected correctly, but read/write errors disappeared.
Maybe worth a try?

I ordered a 6.5GB 5.25" IDE HDD - it just seems like a good piece of hardware to experiment with 😀

Floppies arrived too, so I’m ready to just play around with this setup.

Also, about IDE cables — I’ve read a bunch of things but I’m still confused. How do I tell the difference between an 80-pin and a 40-pin cable? Can a 40-pin cable have both master and slave connectors, or just one drive? I plan to try it and see what works.

LoK wrote on 2025-09-15, 23:28:

ArrayON_56 wrote on 2025-09-15, 22:15:

- Motherboard manufacturer or model is unclear

Full Yes INTEL 82430FX on Intel 430FX chipset.
https://theretroweb.com/motherboards/s/full-y … s-intel-82430fx

Thanks, I thought it is some no-name board.

I see they have newer BIOSes than the one I have.

ArrayON_56 wrote on 2025-09-19, 14:05:

I ordered a 6.5GB 5.25" IDE HDD - it just seems like a good piece of hardware to experiment with 😀

Floppies arrived too, so I’m ready to just play around with this setup.

Also, about IDE cables — I’ve read a bunch of things but I’m still confused. How do I tell the difference between an 80-pin and a 40-pin cable? Can a 40-pin cable have both master and slave connectors, or just one drive? I plan to try it and see what works.

An 80-conductor cable has ground wires interleaved with the 40 signal wires to reduce noise. It is needed for UDMA/66 and higher.
In addition, 80-conductor cables tend to be made so that Cable Select works correctly--one of the 40 leads is cut before it reaches the far-end connector, so that both drives can be jumpered to "CS", and they autoselect "master" (drive 0 in the ATA spec) or "slave" (drive 1) depending on their cable position. It's the same idea as the twist on a floppy cable.
80-conductor cables often have pin 20, the key pin, blocked off, and often a 40-pin cable does not. This can be annoying with old motherboards that have an NC pin at position 20.

Unless you are using UDMA/66...which you are not on a Pentium 133 unless you have added a PATA PCI card... 40 pin is plenty.
80-conductor should work though and I am intrigued as to how going back to 40 pin helped. Unless the 40 pin was shorter length.

Ok, sry for late answer, I went off the radar for a while.

I noticed the difference betwen 40-wire and 80-wire cable now - some IDE cables that I ordered arrived (including 80-wire) and those I was (and am) using are 40-wire ones.
I have the NC pin on motherboard connector, so I even can't connect 80 wire cable.
So cable is not a problem here.

I tried to install Ontrack Disk Manager from floppy, but everytime I run `dm.exe` from diskette, in msdos, everything that happens is blinking cursor, and it won't proceed further (on that p1 pc).

I downloaded the Quantum (Bigfoot) OEM version of Ontrack from winworldpc.com and I tried both:
- write it to floppy drive that I used with RawWrite for Windows on another pc
- just flash the image to usb stick, and emulating it through gotek-like floppy emulator
with same results on that p1 pc

When I connect the bigfoot drive to my main pc through usb to ata adapter, boot it from qemu, and load ontrack diskette image as floppy, dm.exe loads correctly, but I'm not sure if installing it in vm, even if it is on that particular disk, would help.

Also I'm not sure I understand usage of this sw correctly.
You install it on different boot drive that the BIOS can read, and it somehow hooks bios interrupts for disk i/o, thus letting you access bigger drives that the BIOS cannot recognize?
Or you must install it somewhere on first 8 gigs of the drive the BIOS cannot fully access, so the BIOS must be at least be able to read at least some first sectors from it to load it?

Currently I have:
- 5.25" 6.4GB (Quantum Bigfoot TS 6.4AT)
- 3.5" 60GB (Samsung SV0602H)
drives there, and the pc can access the 6.4GB Bigfoot one, but can't access the 60GB one, with every operation failing with Disk I/O error.
I would like to install windows 98 on the bigger one, and just need bios to access it to boot from it.

Can this be really solved with overlay sw, or I just must get compatible drive that the bios can use?
Or alternatively flash the bios...