Pramod Kotwal wrote:
>
> This is about using an IBM PC parallel port to drive a bipolar stepper
> motor. So I hope it not too far off topic here.
> The problem I have is in defining the delay between two subsequent commands
> to write the bit to the port. This time interval will define how fast the
> motor will turn.
>
> The command to wrie data to the port is
> outportb(port address, data).
>
> The interval between writing data is controlled by the
> delay(time) command.
> This command seems to read time in milliseconds.

You can use high res timinbg quite painlessly with the
PC, you sense the PIT timer chip and get a count in
microseconds, (actually 1.194MHz going from my memory)
and you can then loop and sense this count and time
things quite accurately. I did 3 years as a games
graphics engine programmer, had to time everything by
vertical retrace for screen draws.
:o)
-Roman

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics