Very strange floppy issue

[daver2]

There is some good information here: https://www.retrotechnology.com/herbs_stuff/drive.html.

You will have to find the manual for the floppy drive (including the link configuration) and the floppy disk controller.

Dave

 

[dr.zeissler]

If your BIOS setup is set for the B: drive to be 1.44M and not 1.2M you will experience the problem you describe.
Obviously, you are unwilling to see what is actually on the formatted disk using a non-BIOS utility like Anadisk, so I'm going away on this one.

Thank you, my Bios setup entry is correct but there is more on this!

What we found out:
1. Another 360K drive that is working in another machine behaves exactly like my copal. So it's not an issue with the copal.
2. If a software does not use the bios routines to access the drive like VGACOPY or IMD, Win95 etc. the drive is working correctly!
3. 5,25 HD drives (1,2MB) always work on that machine and everywhere (dos/win/os2 etc.)

The issue is that the BIOS of that PC always sets up HD values for 5,25" floppy drives and there is no handshake on that machine
so that the bios is set from HD to DD values (300>250kps / 360/300 spin)

It seems that this is very common that later bios always sets values for 5,25 HD drives, even if you choose 360K 5,25.
But on the first access of the drive there seems to be a form of "handshake" that corrects the bios values from HD to DD.
I recognized that on my P2 with both 360K drives.

I have tested "drvparm" and "driver.sys" to get the wrong BIOS values corrected but both do not work.

so in short: the bios of that machine does not make a handshake for the drive-setting UNTIL I format a floppydisk.
My PII does this if I access the drive.

thank you
doc

 

[dr.zeissler]

There is some good information here: https://www.retrotechnology.com/herbs_stuff/drive.html.
You will have to find the manual for the floppy drive (including the link configuration) and the floppy disk controller.
Dave

Thank you for this!

 

[dr.zeissler]

If your BIOS setup is set for the B: drive to be 1.44M and not 1.2M you will experience the problem you describe...

No, please look in that video there is no 1,44 drive setup in the bios. there is only one single A: drive and that is 360K 5,25 and nothing more.
I disconected the other drive to make sure that there is no other interference and only that single 360K 5,25 drive.

 

[Chuck(G)]

No, please look in that video there is no 1,44 drive setup in the bios. there is only one single A: drive and that is 360K 5,25 and nothing more.
I disconected the other drive to make sure that there is no other interference and only that single 360K 5,25 drive.

As I have said before, if you keep concentrating on the BIOS level operation, you don't really know what's going on with the drive. I've mentioned Anadisk several times to see past the BIOS.