Comment by gumby
13 hours ago
You are forgetting 8” floppies. IBM used only the soft sector ones (one hole punched close to the spindle to mark sector 0) but there were also hard sector ones (a ring of 32 holes close to the spindle hole).
There was a lot of experimentation back in those days. The Wikipedia’s page on floppy disks is surprisingly long!
But those weren't on "IBM PC"-compatibles, just older micros? The 5150 had 5¼" drives. That is: (Q|MS|PC)-DOS never supported 8" floppies, right?
8" floppy drives were not compatible mechanically with IBM PC cases, but there were 8" floppy drives with their own enclosures and power supplies, which could be put on a desktop along the PC case.
IBM PCs have never supported 8" floppy drives, but it was easy to make an adapter between IBM PC floppy cables and 8" floppy drives, so there have existed IBM PC clones from countries where 5¼" floppies were scarce (e.g. Eastern Europe), which supported the attachment of 8" floppy drives.
The original 5¼" floppies had only the size advantage, but they had both a lower capacity and a lower speed than 8" floppies, so attaching 8" floppy drives would have been a higher performance option in the beginning.
Only after the IBM PC/AT introduced the high-density 1.2 Mbyte floppy disks, the 5¼" format matched (actually very slightly exceeded) the performance of the old 8" floppies.
MS-DOS 1.25 supported 8" disks. I think 2.0 still did.
Trust me, I will never forget 8" floppies.
But in the context of drive lettering, although CP/M supported 8" floppies, MS-DOS never did. MS-DOS adopted the naming scheme, but not the boot style.
MS-DOS 1.25 supported 8" disks. I think 2.0 still did.
Floppies, superfloppies, removable hard disks (platter-only, as opposed to modern external hard drives that incorporate the entire drive mechanism), magneto-optical disks, rewritable CD/DVD, even today magnetic tape is still used as removable storage in applications where large capacity is required and shelf life is more important than fast random access.