I thought MS-DOS had special handling for A: and B: since it allowed you to copy from A: to B: even with just one floppy drive.
I thought MS-DOS had special handling for A: and B: since it allowed you to copy from A: to B: even with just one floppy drive.
It does.
https://github.com/microsoft/MS-DOS/blob/2d04cacc5322951f187...
Yes, it did, or something did (maybe the individual commands rather than it being through the OS). I'd completely forgotten about that…
Both of these things are true: commands like diskcopy have special handling to allow the same drive to be used as both source and destination, and the DOS I/O has special handling to request disk changes from A: to B: on single-drive systems for programs that lack specific support.