Slavko Kocjancic wrote: > As I know the EPP should be easy to interface (timing > model) but the hardware is so different and need some pullup's in some > case's. > > Actually, the EPP is a real MESS! The spec is very poorly defined, and the timing between data appearing on the bus and the strobe signals is not specified. Some EPP chips put the data out first, then give the strobe, some do these simultaneously, and there are even some that put the strobe out BEFORE the data! Then, the receive end of the WAIT signal is not always handled well, so crosstalk from the data bus can cause false detection of WAIT releasing, and foul up the timing. > I wan't to see on linuxcnc page some expansion board to address a little > low number of pins on printer port. Just expander not hardware stepgen. > An expander for the parallel port has been discussed before, and seems like it should be relatively easy to do. But, it also slows down the rate at which step pulses can be sent on each axis.
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