DOS ain't dead

How many parallel and serial port can I use in DOS ? (Developers)

posted by RayeR , CZ, 06.01.2013, 21:32

DOS/BIOS mostly covers support up to 2 LPT and 4 COM ports. I think that you may have as many ports you want/fit in the PC but you must be able to assign them different IO address. If you use a PCI card PnP will do it for you. Then you have to write your own handling of such card by your own.
Most of DOS programs rely on fixed legacy IO address like e.g. LPT1 have always base at 378h. But If you have some PCI card you will probably got assigned some high IO base like E000h. At work I have one PCI-E arapter from Axago with 2*COM + 1 LPT and it do like that. Even there was a DOS utility that should set IO bases on legacy addresses it doesn't work (it needs some PCI-PCI bridge reconfiguration for proper IO forwardion which probably the utility cannot do). So I gave up port under DOS. Under windows XP COM ports works fine, LPT for mostly too but for some stupid apps (greeting for ST micro code monkeys) looking directly at legacy address it didn't work too.

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DOS gives me freedom to unlimited HW access.

Complete thread:

• How many parallel and serial port can I use in DOS ? - Damien, 06.01.2013, 16:05 (Developers)
  • How many parallel and serial port can I use in DOS ? - RayeR, 06.01.2013, 21:32
    • How many parallel and serial port can I use in DOS ? - marcov, 07.01.2013, 18:29
      • How many parallel and serial port can I use in DOS ? - RayeR, 08.01.2013, 03:49
      • How many parallel and serial port can I use in DOS ? - Damien, 09.01.2013, 12:58
        • How many parallel and serial port can I use in DOS ? - RayeR, 09.01.2013, 13:40