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3.5" floppy in 5160

k2x4b524[

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720kb drive wants to format to 360kb all the time. Will read 720kb fine, but will only format to 720 through driver.sys. How do I rectify this?

Also,
1.44mb media formatted to 720kb returns data errors constantly. Is there a difference in media recording surfaces and magnetic output of the drive heads?
 
1. Depending on the version of MSDOS, try using DRIVPARM in config.sys. It overrides the default and allows you to keep your drive letter (e.g. B: ) instead of creating new one.

2. Look at the 1.44M media, while a bit different in media characteristics, it's not enough to matter. Just cover the media-sense hole and you're good. Exempli gratia
 
1. Depending on the version of MSDOS, try using DRIVPARM in config.sys. It overrides the default and allows you to keep your drive letter (e.g. B: ) instead of creating new one.

2. Look at the 1.44M media, while a bit different in media characteristics, it's not enough to matter. Just cover the media-sense hole and you're good. Exempli gratia

I just got dos 5 on it so drivparm may be the way to go

And the disks.. I did cover the whole in the 1.44 I used to create. The 720, an old citizen model, has no such hole, so I may have a bad batch of disks then.. Wonderful..
 
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Early on, with the IBM PS/2 line, density was controlled by the host, and not the drive+media. So you often found "holeless" 720K disks formatted to 1.44M. Lousy idea, but I still run across them. I just take them over to the drill press and bore a 1/8" hole in the right place so that they can be read in a "normal" PC drive. Back in the day, there were punches marketed for the cheap-of-mind for just this purpose.
 
I've been formatting down 1.44MB media to 720K for the last 25 years, generally with no issues. But on my Nimbus PC the drive absolutely refuses to format down and will only work with actual 720K DD disks. I realise the hardware has some differences vs an IBM clone but the disk format isn't supposed to be one of them. It would seem that some drive mechs used do have compatibility issues with high density media (I wonder if it comes down to almost all 1.44MB disks coming pre-formatted and some drives cannot generate a strong enough magnetic field to over-write the original formatting?).
 
What are you using to cover the media-sense hole? Some drives use IR sensors; others use mechanical ones.

Otherwise, using a good strong bulk eraser should clear the problem up. I recall some factory-formatted 1.44M floppies that I wanted to reuse (as high-density), but couldn't until I bulk-erased them.
 
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