DOS ain't dead

Can floppy work in nonDMA mode under DOS/Linux/Windows? (Developers)

posted by bretjohn  , Rio Rancho, NM, 04.12.2017, 19:54

> but it's matter for compatability with old SW.

I don't think most software, even the old stuff, uses direct I/O or DMA access anyway. Most programs either depend on DOS (A: or B:) or the BIOS (INT 13h) to access disks, including floppies. I do remember some of the old hard drive backup utilities that used floppies as the backup media used DMA, though I don't remember if they actually _required_ it. I don't remember many other programs even trying to use it. I suppose some games might try to use it too, if they could run off floppies and needed the extra speed.

In my DOS USB disk driver (which also supports USB floppies), I didn't worry about emulating low-level I/O access. Virtualizing I/O is very difficult to accomplish in DOS, and rarely worth the effort. The only program where I've seen a real need to do it is in my USB joystick driver, since almost all programs use direct I/O access for joysticks instead of using the BIOS.

Complete thread:

• Can floppy work in nonDMA mode under DOS/Linux/Windows? - RayeR, 02.12.2017, 21:11
  • Can floppy work in nonDMA mode under DOS/Linux/Windows? - Laaca, 03.12.2017, 22:50
    • Can floppy work in nonDMA mode under DOS/Linux/Windows? - RayeR, 04.12.2017, 02:03
      • Can floppy work in nonDMA mode under DOS/Linux/Windows? - bretjohn, 04.12.2017, 19:54
        • Can floppy work in nonDMA mode under DOS/Linux/Windows? - RayeR, 05.12.2017, 02:27