Vipersan wrote on 2021-10-14, 21:18:

Why is it that some CF cards do not boot ? I have a 512mb and a 1gb CF .. I have successfully got DOS on the 512 which boots no […]
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Why is it that some CF cards do not boot ?
I have a 512mb and a 1gb CF ..
I have successfully got DOS on the 512 which boots no problem..
The Transcend 1GB refuses to boot even though the DOS files were written to it successfully..
I also tried creating an active partition on this CF card ...and then tried to read the partition information using Fdisk ...and no partitions existed even though I just created it with Fdisk.
I seem to remember reading a long time ago that there was a program that could flip a bit on the CF card making it useable as a hard drive...not just as a storage medium.
..or did I dream it ?
rgds
VS

In my opinion these problems are caused by the PC BIOS, I recently solved it, by chance I found the solution, I had a 128MB from SanDisk and a 512MB Unigen, neither of them worked as a boot disk, the PC is a 386DX with BIOS AMI, I haven't tried other cards like 486 or Pentium, but I think it works there too (you have to try).
In short I inserted the 8MB Canon card and set the values ​​(cyln 245) (head 2) (Sec 32) for that card to work, then I replaced it with the 128MB one but I forgot to change the values ​​from BIOS, from Windows 98 boot disk I created the DOS bootable partition, then from DOS I formatted all 128MB without problems (even if there is an 8MB disk in the BIOS).
An important thing in my opinion is not to bring the CF via USB adapter in today's Windows, to load the software I only used floppies, but I think CD-ROMs are fine too.

I've had CF cards that the correct settings are not detected by an older computer. Hook it up to a newer computer and it will detect the correct settings. You can then manually enter the correct settings in the BIOS of the old computer and the card "magically" starts working as expected.

cyclone3d wrote on 2021-10-14, 21:50:

I've had CF cards that the correct settings are not detected by an older computer. Hook it up to a newer computer and it will detect the correct settings. You can then manually enter the correct settings in the BIOS of the old computer and the card "magically" starts working as expected.

I have not explained myself, with the correct settings the CF card does 128MB does not start, while entering the settings of the 8MB card it works, and the 128MB are still detected correctly, and the card starts.

DOS doesn't care about the "fixed disk" flag, it's only an issue with Windows as far as I know.

Did you try running the FDISK /MBR command before partitioning and installing DOS?

Hmm ..looks like a bios flash fixed my problem.
Found and flashed 4SAW0911 and replaced the bios chip on my SOYO 4SA2 mobo ..
The transcend 1gb CF is now seen as LRG mode4 1020mb ...and now boots DOS6.22
I'm calling that a win for tonight..

TheMobRules wrote on 2021-10-15, 00:02:

DOS doesn't care about the "fixed disk" flag, it's only an issue with Windows as far as I know.

Did you try running the FDISK /MBR command before partitioning and installing DOS?

Ah yes ..that was it ..the fixed disk flag...I knew I hadn't dreamt it...
not that it would have helped.
I guess the bios just wasn't recent enough.
see my post above this one.
cheers anyway.

After that success ...I'll finish off by uploading a couple of photos of the SOYO in my new mobo test bench...now complete.
Very useful for tackling problems ..with access.
fitted with 40 nylon M3 standoffs that can be left in place with any mobo ..and no risk of shorting anything out.
A worthy project build I think you'll agree.

Vipersan wrote on 2021-10-15, 00:24:

After that success ...I'll finish off by uploading a couple of photos of the SOYO in my new mobo test bench...now complete. Very […]
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After that success ...I'll finish off by uploading a couple of photos of the SOYO in my new mobo test bench...now complete.
Very useful for tackling problems ..with access.
fitted with 40 nylon M3 standoffs that can be left in place with any mobo ..and no risk of shorting anything out.
A worthy project build I think you'll agree.

I wrote that it was a BIOS problem!
Anyway I have to congratulate you again, for the excellent work, both for the CF and for the test bench.
I don't have something like that, but it could be useful, currently I mount spacers in Motherboards, this allows me to have up to three boards on a self-made 60x80cm bench, and also to place one or two 17 "and 19" monitors on it. .
I am currently at work installing on CF, old software on a 386DX and a 386SX, if you want you can also switch to other PCs from 486 upwards.
In the photo you can see the counter without the top.
among the software that I am installing the first versions of windows, at the moment 1.03IT and 3.0IT, but I will also try the 2.

Vipersan wrote on 2021-10-15, 00:09:

Ah yes ..that was it ..the fixed disk flag...I knew I hadn't dreamt it... not that it would have helped. I guess the bios just w […]
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TheMobRules wrote on 2021-10-15, 00:02:

DOS doesn't care about the "fixed disk" flag, it's only an issue with Windows as far as I know.

Did you try running the FDISK /MBR command before partitioning and installing DOS?

Ah yes ..that was it ..the fixed disk flag...I knew I hadn't dreamt it...
not that it would have helped.
I guess the bios just wasn't recent enough.
see my post above this one.
cheers anyway.

Certain that is not it.
you're thinking of the Removable bit.
https://www.os2museum.com/wp/removable-cf-card-or-not/

which, as was mentioned, shouldn't be any problem in plain dos.

Well ..it matters not since the CF now works ..and as you say is not important as far as DOS is concerned.
cheers anyway Weedeewee