As I remember right, I think that there is a ready signal that the printer has to hold high for the interface to clock out data. Been quite a few years since I looked at a centronics interface schematic though. Chris Schumann said: > Hey guys, > > I've got a little electronics project I'm working on, and I > need to send pulses out from a PC that's got Red Hat 9. > > I thought the data strobe on the parallel port would be a > perfect way to do this, and I'd like to avoid writing "real" > program, so I'd like to do it using a shell command. > > The external device takes TTL levels, which are abundant > on the parallel port. I'm hoping to use just two wires. > > I tried changing permissions on /dev/lp0 to a+wr and > doing "echo > /dev/lp0", but it didn't work. > "echo > file" puts just a newline in file. One byte. > > Echoing to the port hangs, perhaps waiting for an > acknowledgement. > > I've also tried looking around for a HOWTO, but it's > so involved and requires programming (which I can do, > but would like to avoid). > > I'd appreciate it a lot if someone would point me to > a site I can read to knock this out. Thanks. > > Chris Schumann > > (Hmmm... maybe I can connect the STROBE to ACK pin...) > > > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > http://www.mn-linux.org tclug-list at mn-linux.org > https://mailman.real-time.com/mailman/listinfo/tclug-list _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota http://www.mn-linux.org tclug-list at mn-linux.org https://mailman.real-time.com/mailman/listinfo/tclug-list