IBM XT boot floppy

[souler]

I had DOS 2.0 boot floppy working fine on my IBM XT. Copied a little program to the disk with my windows 2000 machine then it doesnt boot anymore on XT.
So i dont have a working boot disk anymore, how can i make one on my win2k pc? I have tried to make one by moving XT's full size floppy drive to windows pc, formatting the disk to 180kb, and everything but no success.

 

[mbbrutman]

First: Don't stick old floppies into the drive of a machine running any flavor of Windows without write protecting them first. Windows is kind of aggressive about writing onto floppies for no good reason.

Second: backups are necessary. Now you know why.

The best thing to do would be to find another machine running DOS and make a boot diskette on that. You can also use your Windows 2000 machine with a disk imaging program to write a 'snapshot' back onto the diskette. (You will need to have somebody mail you an image of a DOS bootable disk, or find one online.)

 

[souler]

First: Don't stick old floppies into the drive of a machine running any flavor of Windows without write protecting them first. Windows is kind of aggressive about writing onto floppies for no good reason.

Second: backups are necessary. Now you know why.

The best thing to do would be to find another machine running DOS and make a boot diskette on that. You can also use your Windows 2000 machine with a disk imaging program to write a 'snapshot' back onto the diskette. (You will need to have somebody mail you an image of a DOS bootable disk, or find one online.)

I have tried to boot that win2k machine with DOS floppy, "sys b:" and copied command.com to the disk. Doesnt work. Neither does if i write disk image to the floppy. I have tried DOS 3.2, 2.1 and 4.0 but it just doesnt boot with XT. Have tried several 5.25" drives including the XT's full size drive.
Maybe i need to put a MFM-controller and my ST255 to other computer and install DOS to it (It's empty).

 

[mbbrutman]

I have a better idea .. if you boot the new machine using an old DOS, you can format and put the OS on the diskette using the /s option of format. For example:

format a: /s

I'm assuming you are booting from a 3.5" diskette, which is why you just can't diskcopy the DOS disk onto the 5.25. But the format command above should work just fine.

 

[souler]

I have a better idea .. if you boot the new machine using an old DOS, you can format and put the OS on the diskette using the /s option of format. For example:

format a: /s

I'm assuming you are booting from a 3.5" diskette, which is why you just can't diskcopy the DOS disk onto the 5.25. But the format command above should work just fine.

I boot win2k machine from 3.5" disk (with several DOS versions). Isn't "sys b: , copy command.com b:" same than format /s ?
Have tried both but no success, diskcopy of course doesnt work because different disk sizes.. I have tried to put DOS disk image to 5.25" disk but it just doesnt work..

 

[mbbrutman]

You are correct - format /s should be equivalent to format, sys, and then copying command.com. It is less steps to do though, so it should be foolproof.

I don't understand why it is not working. Are you using a Double Density disk in the 5.25" drive? Using a high density disk will not work reliably, as the double density drive in the XT doesn't work well with high density media.

 

[carlsson]

If I'm not mistaken, writing a DD disk in a HD drive may not always result in a disk readable in a DD drive, although the media is correct.

 

[mbbrutman]

That is true of modern 3.5" drives - they will automatically detect the media type and write the data accordingly.

I'm not entirely sure if a 5.25" drive can sense the media .. I don't think that it can. It probably tries both data rates, and if the HD data rate fails it uses the lower DD data rate. Either way, it can't reliably write to a DD diskette with 40 tracks because the head on the 5.25" drive is too narrow.