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- Subject: Re: Fast serial (was: misc kernel patches... (mostly tty stuff))
- Date: Wed, 14 Jul 93 16:21:46 CES
- From: Juergen Lock <nox@jelal.north.de>
- In-Reply-To: <9307122110.AA04284@terminator.rs.itd.umich.edu>; from "Nicholas S Castellano" at Jul 12, 93 5:10 pm
- Message-Id: <9307141421.AA00212@jelal.north.de>
-
- Nicholas S Castellano writes:
-
- > > and i still think that MiNT needs better ways to do fast RAW serial IO,
- > >access modem control lines and speeds >19200, change Iorec buffer sizes,
- > >etc.. but i'll repeat that only if you want it. :-)
- >
- > I agree...But I think most of this can be done with a standalone modem
- > driver as opposed to being in the kernel.
-
- ok! but that still requires changes in MiNT. for example currently it
- seems a 1K tty read gets _always_ translated into 1000 device reads of
- each one char, that just cant be fast no matter how good the driver is...
- and to get it real fast such a driver would also need a way to tell
- MiNT that it reads and writes bytes, not longs. then it could get a
- RAW 1K read or write as that and just bcopy the data. (and also sleep
- gracefully when it waits for more than a few bytes to go over the port
- so it doesn't have to waste so much CPU time...)
-
- or things like TIOCCAR/CLOCAL, HUPCL.. they probably need some help
- from the kernel too.
-
- > I've been thinking recently
- > that most of my TOS 1.0 hacks in MiNT's rsconf() code should really be
- > in a standalone device driver as well (especially since that code
- > still doesn't work terribly well.)
-
- well either this, or just forget about those 1001 TOS bugs and tell
- people to use one of the serial port fix TSRs available, some of them
- now even work. :)
-
- and for a standalone modem driver rsconf (and iorec) would better just
- translate their parameters into device ioctls, right?
-
- > In one of my conversations about the serial port with someone (I think
- > it was someone on this list) I was told that there was already a
- > driver along these lines that was mostly completed, but I haven't
- > heard anything about it since then.
-
- hmm i hope you don't mean me :) i only have a hacked serptch2 to
- replace buggy TOS routines, ([Bx]co*, Rcsonf, Ioctl...) but it doesn't
- know about MiNT. the fast IO stuff i did for taylor uucp does it all
- itself... (and it has to `guess' the physical device with ttyname
- because i found no other way to get it from an fd) but of course it
- could be useful for writing such a driver... its in tuu103d3.zoo on a.a,
- look at the diffs for sys2.c.
-
- other than that i only know of someone who seems to hate MiNT so much
- that he wrote a fast driver that tries to act like MiNT, but for TOS!
- (looks for Fopen ("u:\dev\modem1"..) and then handles Fread/Fwrite
- itself or so... i guess if you could read all those maus news you'd
- sometimes just shake your head... :-)
-
- cheers
- Juergen
- --
- J"urgen Lock / nox@jelal.north.de / UUCP: ..!uunet!unido!uniol!jelal!nox
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