IBM 9331-011 8" External Floppy Drive - eBay 183038271095

Fred Cisin cisin at
Thu Feb 1 16:45:28 CST 2018

>> The drives that where used on the AS/400 are all "industry standard" 
>> drives so it should be easy to adapt one to a PC.
On Thu, 1 Feb 2018, Grant Taylor via cctalk wrote:
> The drives may be standard, but I am curious how standard the format of 
> what's on the disk is.  How likely is it that a PC OS from the last ~30 
> years will understand how to read what's on the disk?
> Or, I'm guessing it's likely that archival programs don't need to 
> understand how to read the disk format for raw disk imaging.

DOS/Windoze will have absolutely no idea how to understand what is on the 

It is a different file system structure, and DOS/Windoze didn't deal with 
THAT is why there existed programs such as 22Disk, XenoCopy, Uniform, etc. 
to interpret the file system of disks from CP/M, P-System, TRS-DOS, etc.
that had different file system structures, but similar recording methods.

There were somewhere around 2500 mutually incompatible floppy formats.
(XenoCopy included capability for 400 of them)

If the physical track structure is "standard" MFM, then it is possible to 
read sectors from them.  That means that Imagedisk, Teledisk, or a disk 
file transfer program that has implemented THAT format can read them.

If the physical track structure is different, even if using the same disk 
drive, such as hard-sector, MFM without similar sector headers, MMFM (FM 
sector headers, MFM data), or GCR (Apple, Commodore, Sirius/Victor, etc.), 
then you can not read sectors using a PC FDC chip.  Nevertheless, flux 
transition, such as Kryoflux, Cat Weasel, Option Board, can still capture 
the raw flux transitions, and maybe make sense out of them.

Grumpy Ol' Fred     		cisin at

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