Date: Wed, 25 Nov 1998 21:13:50 -0800 From: Mike Smith <mike@smith.net.au> To: myers@iname.com Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: Non-kernel hacker needs serial help! Message-ID: <199811260513.VAA00609@dingo.cdrom.com> In-Reply-To: Your message of "Wed, 25 Nov 1998 12:00:02 PST." <199811252000.MAA01573@sol.>
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> > > Folks: > > Help a non-kernel hacker out here. I've got an ancient HP DeskWriter > printer with a serial interface. It came off a Macintosh. Specs are > 57.6K, 8N1. Under Win98, I can make it print, but only after > manually specifying a slowed transfer rate from the UART (under > "Advanced Port Settings", or something like that). However, I can't > make it print at all from my FreeBSD box. > > Or rather, it will print, but only the first two inches or so of the > first page. After that, it just hangs. > > So, I speculate: Macs must have a non-standard H/W handshaking > protocol. The FreeBSD box never sees a "buffer full" message from the > printer, so it blindly blasts out the bits, but the printer barfs on > them, and ends up flushing its buffer and giving up. It only makes it > through two inches of output before dying. > > My solution: introduce a delay into the serial port output stream, just > like Win98 lets me do. I go kernel hacking. I locate > /usr/src/sys/i386/isa/sio.c, find the function siointr1, and throw in > two DELAY(1000) statements, like this: Bad. Fix your cable and the port settings to handshake properly. There's probably a Linux FAQ about this somewhere; most of it should be applicable. -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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