[PARPORT] patch-2.2.5-tmw1

Tim Waugh (tim@cyberelk.demon.co.uk)
Wed, 31 Mar 1999 21:40:01 +0100 (GMT)

Okay, patch 2.2.5-tmw1 is (or will be) available at:


Change list at <URL:http://www.cyberelk.demon.co.uk/parport.html>.

One of the new things is lp_poll: you should now be able to
select(open("/dev/lp0"), ...). Unfortunately this doesn't work for me,
and I think it's my printer's fault.

After each lp_write, we check to see if there is data -- we do this by
negotiating to reverse nibble mode and checking nDataAvail. Now, my
BJC-210 rejects negotiation to that mode, against the spec.. except if
there is data in its write buffer, in which case it accepts the
negotiation but doesn't print anything until we switch to forward mode

I'd hoped that we'd be able to leave the printer in reverse nibble mode
when we're not using it, so that it can shake nDataAvail (nAck) and let us
know to try reading. It looks like we might have to revert to polling
once a second or something awful.

I'm hoping that this is a bug in my code rather than a hardware thing, so
please test this out. The symptoms to look for are (a) printing doesn't
work, and (b) printing works again after #defining BROKEN_PRINTER in lp.c.

Let me know,

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This archive was generated by hypermail 2.0b3 on Wed 31 Mar 1999 - 15:48:32 EST