VOGONS


Reply 20 of 26, by darry

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kikendo wrote on 2020-06-16, 22:11:
OK I am more confused than before. I did a lot more tests, and I managed to format a bunch of 360KB disks, but not all. Also the […]
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OK I am more confused than before. I did a lot more tests, and I managed to format a bunch of 360KB disks, but not all. Also the only 1.2MB disk I have, I couldn't format (same error, track 0 unreadable). I made a MS-DOS 6.22 boot disk which seemed more successful at formatting disks than the Windows 98 DOS boot disk I had before. Could it be that Windows 98 had something to do with this, too?

The weird thing is that the disks that I can't write to on the PC I can write to on my C64.

I think the drive is fine, but maybe it's more sensitive to media on the verge of bit rotting, which might be read OK but losing density to be written on.
I would have to buy a box of new old stock 2HD disks to do more tests, but for now I feel like I spent way too much time with this unit.

Are the disks that work only on your C64 single-sided ?

Reply 21 of 26, by babtras

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Not that it will help right now, for Googlers of the future I'll note that I just wrote an image to a 40 track 360k 2S-2D disk with a Panasonic JU-475-4 (1.2MB drive). It then booted and read and wrote on an Epson SD-521, 360k-only drive in an 8088. So I can attest that those particular models seem to work ok for this purpose

Reply 22 of 26, by pentiumspeed

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There is no solution and best way to do this is obtain 360K floppy drive and use this. The magnetic flux on 360K and 1.22MB floppy disks are completely different also.

Or obtain 1.22MB floppy disks and use it only to store stuff on 1.22MB floppy drive. And read *only* the 360K disks on 1.22MB drive.

Cheers,

Great Northern aka Canada.

Reply 23 of 26, by Horun

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kikendo wrote on 2020-06-16, 22:11:

OK I am more confused than before. I did a lot more tests, and I managed to format a bunch of 360KB disks, but not all. Also the only 1.2MB disk I have, I couldn't format (same error, track 0 unreadable). I made a MS-DOS 6.22 boot disk which seemed more successful at formatting disks than the Windows 98 DOS boot disk I had before. Could it be that Windows 98 had something to do with this, too?

Yes ! DOS 7.1 (Win98) is a bit different for working with floppies than real DOS (5 or 6.x) or DOS 7.0 (Win95). It is a known problem for some of us....
https://support.microsoft.com/en-us/help/1400 … gnized-by-windo

Hate posting a reply and have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. 🤣 Second computer a 286 12Mhz with real IDE drive ! After that came 386, 486, Pentium, P.Pro and everything after....

Reply 25 of 26, by kikendo

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darry wrote on 2020-06-16, 22:15:

Are the disks that work only on your C64 single-sided ?

No, they were all 2SDD. Also I am using a 1571 and formatting full double sided.

Horun wrote on 2020-06-16, 23:46:

Yes ! DOS 7.1 (Win98) is a bit different for working with floppies than real DOS (5 or 6.x) or DOS 7.0 (Win95). It is a known problem for some of us....
https://support.microsoft.com/en-us/help/1400 … gnized-by-windo

OK then I was running into that trouble on the Pentium II setup I guess! Good to know.

maxtherabbit wrote on 2020-06-17, 00:47:

did you clean the heads yet? That would have been the first thing I tried

Yeah, I cleaned the heads thoroughly.

pentiumspeed wrote on 2020-06-16, 23:17:

There is no solution and best way to do this is obtain 360K floppy drive and use this. The magnetic flux on 360K and 1.22MB floppy disks are completely different also.

As I wrote above, I also tried a 1.2MB disk with similar results.
And I already managed to format 360KB disks on the 386, just not all of them (using format /4)

Reply 26 of 26, by BoraxMan

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This might sound strange, but in desperation when this happened to me, I opened the disk drive, and manually moved the heads up from their default position. Then I used the disk by formatting one (with the cover off, so I could see the heads in operation). After a couple of times of letting the heads move to their default position, and moving them back up manually., I was able to format the disk successfully, where previously the format would fail, either at the start, or at the end.

Note, this happened to me TWICE one one disk drive, and both times, this "solution" fixed it.