Parallel port
Ned Konz
ned at bike-nomad.com
Sun Apr 7 19:00:31 UTC 2002
On Sunday 07 April 2002 11:30 am, ducasse wrote:
> Apparently they were under Windows and want to switch to linux.
Under Linux, the best way (probably) is to use /dev/parport* (the ppdev
driver).
The easiest way is to enable access to the IO ports and do byte read/write.
You enable access using ioperm or iopl, which can only be used by root. If
this doesn't bother you, you can make a set uid launcher that does an ioperm
call to enable access to the parallel port hardware and then exec's Squeak.
If you do this, you have to make sure that neither the lp nor ppdev drivers
are loaded (you could dynamically unload them if they were modules). ioperm
is inherited on exec.
http://people.redhat.com/twaugh/parport/html/
> What the guy told me is that they have on bit per motors so they can have
> up to 16 motors.
Since when are there 16 output bits per parallel port? Are they using latches
or something? At best, you've got 8 data bits and a few output control bits
(strobe, autoLF, init, select) from the parallel port hardware.
http://www.lvr.com/parport.htm
http://et.nmsu.edu/~etti/fall96/computer/printer/printer.html
--
Ned Konz
currently: Stanwood, WA
email: ned at bike-nomad.com
homepage: http://bike-nomad.com
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