5.25 Floppy Disks - 96 TPI vs 48 TPI

Ricoche · Joined: Dec 19, 2009 Posts: 7 Location: Nagano, Japan

I'm curious about the 5.25 floppy disks that can be used with the Yamaha QX-1. In the manual the recommended floppy disk is as follows:

Maxell 5.25
Double-Sided
Double-Density
Double-Track 96 TPI
80 Tracks/Side

If correct, I believe a 96 TPI means 720KB for the Yamaha QX-1. I am particularly interested in whether a floppy disk with 48 TPI will also work. This would be 360KB if I understand 5.25 floppy disks correctly.

I noticed that it's not too difficult to find 48 TPI disks, but rather difficult for 96 TPI not to mention more expensive.

Thanks for any insight into this.

Jim

elmegil · Posted: Mon May 06, 2013 7:59 pm Post subject:

http://en.wikipedia.org/wiki/Floppy_disk_format

it depends on whether it's soft sectored or hard sectored. For a soft sectored drive, it ought to be possible. Worth trying, since the worst that would happen is it wouldn't work.

Well, actually the WORST that could happen is it works briefly and then you lose your sequences Smile

DrJustice · Posted: Tue May 07, 2013 6:42 pm Post subject:

The track density isn't directly connected to soft/hard sectors. Anyway, soft sector is (was!) most common. The TPI rating just tells which track density the media is certified for (48TPI = 40 cylinders, 96TPI = 80 cylinders). AFAIK, back in the day, all (most...) floppy disk were made more or less equal, and the TPI rating was found by testing every Nth disk, then batches were sorted into SD or DD ratings. When I was a lad we just used what we had, and the general experience told me that price and TPI rating did not correlate well with actual reliability. It was more about the format of pre formatted disks - e.g. there were expensive Dysan DD disks that were crap vs. unmarked cheap brand-x disks that had much better reliability, whatever density you ran them at. Just grab what you can get your hand on and try...

elmegil · Posted: Tue May 07, 2013 6:54 pm Post subject:

I thought hard-sectored drives would enforce "you must only use disks with this combination of hole punches" or whatever it was that "hard" sectored them?

DrJustice · Posted: Wed May 08, 2013 3:32 am Post subject:

Yes they do, but the track density is not tied to the sector indexing. Is the drive in the QX-1 a hard sector one? You can get new floppys from a few suppliers, Amazon has them, and this shop, but probably only soft sector ones.