I think different cards report different CHS values. You could try putting it in a machine that autodetects CHS values and write those down.

Run the attached utility on the machine you have the CF connected. Define nothing in BIOS, boot from a floppy and run it.

I'm assuming that your question is about machines that don't have an auto-detect option in BIOS. In this case using the auto-detect feature of another machine to get the values is dangerous, unless you are absolutely certain what you're getting. Usually, not always of course, PCs with auto-detect also have LBA.

Could you explain how it could be dangerous when copy pasting CHS values? Would like to know.

starquake wrote:

Could you explain how it could be dangerous when copy pasting CHS values? Would like to know.

Nothing will explode 🤣 Auto-detecting a card on a PC supporting LARGE/LBA might give you wrong values for a pure CHS-capable BIOS. To be honest smaller cards mostly come out correct, but larger and newer CFs sometimes return very weird geometry, nothing like a mechanical disk. There's no problem with this approach, you just need to understand what values you're getting and if they make any sense. I mean you may end up with values that are even outside the range of what you can enter on a CHS-only BIOS.

Oh okay, but my BIOS reports values for LBA, LARGE and CHS. I would be able to use CHS in that case right?

If your BIOS supports LBA, then I'm almost certain that it has HDD auto detect. Just use it. With CF larger then 1GB use LBA, otherwise use CHS.

I was talking about the same scenario that the OP was talking about. Using autodetected CHS values for a machine that does not do autodetection.

In other words: I'm safe using the autodetected CHS values (not LBA or LARGE) in a machine that does not have autodetection, right?

EDIT: OP was not talking about doing that. Disregard that statement.

starquake wrote:

In other words: I'm safe using the autodetected CHS values (not LBA or LARGE) in a machine that does not have autodetection, right?

Yes, that's what I meant by "understand what you're doing". If you can do an auto-detect and force CHS, of course go ahead and do it, it's all good. Not all BIOS however allow you to choose mode (CHS/LARGE/LBA) when using auto-detect, that's why I made that comment -but obviously didn't explain it enough.

@kixs: starquake is not the OP 😉

Wow, thanks! The IDEINFO.EXE worked! I had been struggling to get the geometry for a 256MB card. Since I don't have a regular PC anymore, this was the only way on my 286. 😀

Are all 256mb CF Cards the same CHS settings or can they vary?

FYI
I used IDEINFO program to detect HDD geometry for OneFavor 256MB card.
This detected number system was very unstable. Broken FAT, bad blocks and other weird things.
I asked ChatGPT for the same and provided number instantly "fixed" CF card.
So, don't trust blindly this utility. I was about to make a conclusion that I got defective or non-IDE-to-CF adapter supported card.

djyuran wrote on 2024-09-28, 00:50:

So, don't trust blindly this utility.

This utility does not detect and does not guess, it shows the data as it reported by the card itself.
Whatever issue you had - it's not with this app. It's about actual partitioning of the card, the possible geometry translation mode used when partitioning/formatting the card (like maybe you've used LBA mode when formatting it in cardreader), and the possible differences between this translation and the geometry specified later - any mismatch will cause the data appear differently for PC.

ldare1000 wrote on 2023-08-27, 20:29:

Are all 256mb CF Cards the same CHS settings or can they vary?

“Geometries” will vary depending on the controller inside the cf, the flash memory used, and the internal firmware. Solid state devices don’t even have a real geometry because there are no spinning disks, so yeah, it’s all make believe and different vendors pretend different things.

To go a step further, since the introduction of IDE storage, the storage devices have been able to translate external CHS values into something they can use, whether flash or spinning disk. Most IDE devices will adjust to whatever geometry you enter as long as you don’t make the size larger than the device can handle. But if youwant to use it on a PC, your bios might have issues.
1) dont do more than 63 sectors per track
2) dont do more than 1024 cylinders for bios older than june 1994 (512mb limit)
3) don’t do more than 16 heads for bioses older than 1997 (8gb limit)
The drive table might let you enter larger values, but the chances of them working reliably are slim.

IDE devices made after 1992 generally support an ATA info command that reports an optimal geometry. The tool shared in this thread accesses those values. You dont have to use the optimal geometry but the downside with randomly selecting approximate geometries is that:
1) you might not be using the full capacity of your device
2) if you lose the random settings you entered, it gets hard to access your data again
3) your device won’t work as expected if you use it on a computer that only works with auto detected geometry

So it is usually best to use the autodetect geometry.

LBA is a thing that helps you avoid the CHS complexity, but you rarely see that functionality on bios older than 1997 or storage devices older than 1995.