No announcement yet.

VCOMM - Getting the COM signals ...

  • Filter
  • Time
  • Show
Clear All
new posts

    VCOMM - Getting the COM signals ...


    I'm trying to get a signalling overlook on the COM-ports,
    right down to the individual pins inside Windows. Not being very
    skillful at hardware programming, I've found (and heard of)
    VCOMM.H in C and set forth to MSDN to investigate this further ...

    So I'll now try all of you, out there in PB-land ...
    How to use something like that?

    I want a fully controllable COM-port, w o any programming skills
    over my minor capacity!!! I'd made it in DOS but that's another
    story, or isn't it ???

    Please ... someone ...???


    Maybe some of the goodies at may be of help? It certainly would be easier than rewriting a C-code COMM library.

    Essentially, you can use inline-assembler to manipluate ports, but only under Windows 95/98/ME. Under NT/2000, you must use a kernel-mode driver (similar to a VxD used in Win9x/ME). You should be able to find the necessary libraries at Lake View Reasearch.

    PowerBASIC Support
    mailto:[email protected][email protected]</A>
    mailto:[email protected]


      The easy solution is PowerBASIC's own built-in comm handling. See the COMM function
      and COMM statement in the PB help or manuals.

      If this doesn't offer you enough control, the Windows comm APIs are very flexible,
      but can get fairly complicated.

      If you still need more, you're probably going to need a custom device driver, which
      is liable to be yet more complicated and likely expensive.

      Or, perhaps it would be reasonable to have your Windows program interact with your
      DOS comm program, if you already have a DOS program that suits your needs.

      Tom Hanlin
      PowerBASIC Staff


        If you need a kernel level driver for NT/2000 get the one from It's free and works well. You need to fiddle with
        the delaration file to change the alias to "C mangled" names. Use
        Dependency Walker (depends.exe) to get the correct names.

        "There are two novels that can change a bookish fourteen-year old's life: The Lord of the Rings and Atlas Shrugged. One is a childish fantasy that often engenders a lifelong obsession with its unbelievable heroes, leading to an emotionally stunted, socially crippled adulthood, unable to deal with the real world. The other, of course, involves orcs." - John Rogers