help installing external 3.5 inch floppy low capacity floppy disk drive

Camelot wrote:
Got a friend with an old PC?

Uh, no, I don't.

And the only PC compatibles I have, are broken or defective. (I really can't tell the difference.)

Sounds like a USB stick, a six-pack and a couple of hours at a friend's house is in order.

When I bought a pair of 3.5" floppy drives with USB 2.0 ports, the packages said they supported 720K and 1.44 megs, but when I tried them out, they didn't work. They wouldn't read the floppy disks I had. I am not a PC user, so I expect something to help me out in this regard. Maybe some kind of user-friendly program (with an appropriate driver) with lots of prompts and help menus. But no such luck. I'd really like to rescue my data.

Kurt Lang wrote:
Other World Computing has this one for only $38. It's actually kind of nice in that it will read 720K disks. Most external floppy drives I've seen for the Mac will only read 1.44 MB disks.

Did you buy one? And it worked when you tried it out?

Kurt Lang wrote:
Sorry, no. I just pointed that one out in particular because it can read lower density disks. But I haven't had a need to purchase one. On the plus side, items from OWC tend to be very good to excellent quality. They also have a generous, pretty much hassle free return policy.

Uh, oh. Just noticed on that page that it says, "Mac Format 2DD diskettes are not supported." Which means it won't read typical 700K low density Mac disks. It is fine for 720K MS-DOS formatted disks though. Since that's what you state you're mostly trying to read, it'll still work for you.

What I have mostly, are 360K disks. And then there are a bunch of 720K disks. And some (not very many) 1.44 meg disks.

And speaking of obscure disks, I have some Commodore "3.5 inch" disks, too. They are 800K, if I remember right.

Now, so far as I can tell, the only practical way of backing this kind of stuff up, is buying a vintage (i.e., antique 1980s) computer, and then transferring all that stuff by modem to modem transfer... (So how DO I go about configuring my Mac mini to support Xmodem, Ymodem, or Zmodem file transfers at 2400 baud?)

Kurt Lang wrote:

What I have mostly, are 360K disks. And then there are a bunch of 720K disks. And some (not very many) 1.44 meg disks.

Well, the drive I linked to will work for your PC formatted 720KB and 1.44MB 3½" disks. Finding a working 5¼" drive for those 360KB disks could be much more difficult.

I fear there is a communication gap here. The 360K diskettes measure 3.5" and fit in a 3.5" drive. The File Allocation Table is the key here. While I am not a PC programmer in any way, shape, or form, I understand that the 'size' of the FAT specifies how far the read head must be stepped before it gets into actual track and sector information. Even worse, there are different kinds of File Allocation Tables. (I am much happier with my Mac mini - the way it manages disk files - and look desperately for a way of rescuing my data.)

It may be a matter of finding an old PC that you can copy all of the floppy's contents onto its hard drive. Best bet would be to have a PC with an IDE hard drive. Then you could take it out of the PC and mount it in your G5. The Mac should be able to access a FAT16 MS-DOS drive.

Sigh

Kurt Lang wrote:

I fear there is a communication gap here. The 360K diskettes measure 3.5" and fit in a 3.5" drive.

No problem. Our first computer was an IBM XT clone with a 5.25" 360K drive. I built quite a few PC's during the changes from 8088 to 286, 386 and so on.

When 3.5" drives came out, I just don't ever remember seeing them available for 360 KB disks. The first I ever heard of were 720 KB DD. Then the 1.4 MB HD disks and drives came out.

Edit: I've been doing quite a bit of searching on the web just now. As I thought, there never has been such a thing as a 360KB 3.5" disk. All references to 360KB is for 5.25" drives. Wikipeda shows the same. All references to 360KB is for 5.25" drives. 720KB was the lowest form of 3.5" drives

http://en.wikipedia.org/wiki/Comparisonof_x86_DOS_operatingsystems

The Atari ST has a disk drive that formats 3.5" diskettes with 360K. The reason that it is 360K, is that it has only one R/W head. It's what is called a Single Sided Disk Drive. I don't exactly understand File Allocation Tables. It might be a 12 bit FAT, maybe some kind of a weird 16 bit FAT.

It is said to be PC compatible. Unfortunately, the Atari-compatible "Double-Sided Disk" Drive has nothing but trouble with diskettes that were formatted on both sides "at the factory," and which are then reformatted on just one side, "at home." The spurious data on the second side (because of the factory format disagreeing with the home format) makes it doubt that the diskette is really what it appears to be.