Post AXWkbJgpEpCdtI8qxc by PurpleCat@pleromaundermybed.ddns.net
 (DIR) More posts by PurpleCat@pleromaundermybed.ddns.net
 (DIR) Post #AXWkbIrmIcMzKyG5OS by dec_hl@mastodon.social
       2023-07-07T19:17:04Z
       
       0 likes, 0 repeats
       
       I face an interesting problem for a file selection dialog I want to create:How do I detect which drive letters are actually available/used in #MSDOS (using either #DJGPP or a DOS/BIOS INT)?I guess it is always safe to assume A, B and C are there?What happens when no secondary disk drive is installed?I found _dos_setdrive() in DJGPP and INT21 0Eh, but I'm not sure what happens when I _set_drive() with a non existing drive?http://www.delorie.com/djgpp/doc/libc/libc_179.htmlhttp://spike.scu.edu.au/~barry/interrupts.html#ah0e
       
 (DIR) Post #AXWkbJgpEpCdtI8qxc by PurpleCat@pleromaundermybed.ddns.net
       2023-07-09T19:15:01.982926Z
       
       0 likes, 0 repeats
       
       @dec_hl On the NEC PC-9801, you have another dillema. The drive you boot from is A: if it's the first hard disk (IIRC) or the first floppy disk. If you boot from floppy drive #2 however it becomes B:So on a PC-98, A: can be your first floppy if you boot from it or the first HDD if you boot from it, B: is your second floppy or first HDD if you have a single floppy and also your first HDD if you boot from a single floppy machine, and C: is your first floppy on a dual floppy machine if you boot from a floppy disk.So Japanese DOS programs when installing will ask for the HDD letter and not assume it's anything.
       
 (DIR) Post #AXWkbKfna7yYwOfY00 by dec_hl@mastodon.social
       2023-07-07T19:17:34Z
       
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       The return value is "the highest drive present", so that won't help me with gaps (e.g. A present, B isn't, C is, D-W are not and X is a mapped network drive).Also, there is the 'undocumented' INT21 32h. Would that work for network-drives as well?https://stanislavs.org/helppc/int_21-32.htmlWhat would be the best practice to only find available drives (like e.g. DosZip file commander does)?