> > Do we currently use DMA for this kind of thing, when it's available?
> No, not yet -- feel free to add appropriate support!
PLIP over ECP might be _very_ interesting (although I'm not sure it will
run without small hardware hacks -- I don't remember the ECP specs well, but
I recollect something about the protocol being a bit asymmetric).
> The problem is that the driver architecture would be completely different:
> * the current PLIP cable is a 5-bit full-duplex cable, connecting
> one computer's output-only (usually) data lines
> to the other one's read and read-write control lines.
By the way, Configure.help mentions a 8-bit mode which was never supported :)
> * In current driver, IO is done by IRQ (packet start) then
> polling (packet reception), with 4 data bits (nibbles) and 1 control bit
> to acknowledge every nibble.
> The architecture is quite suboptimal, but very robust,
> and works on just any PC parallel port (I used in 0.99.15 times
> to connect a 486dx33 laptop to a 386dx33 desktop),
> without timing dependencies.
No, it doesn't run on PC's with IRQ-less parallel ports (unfortunately,
I happen to one of them).
Have a nice fortnight
-- Martin `MJ' Mares <mj@ucw.cz> http://atrey.karlin.mff.cuni.cz/~mj/ Faculty of Math and Physics, Charles University, Prague, Czech Rep., Earth "Got mole problems? Call Avogadro, 602-1023!"- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu