[comp.os.minix] Rs232 on Minix-ST

mills@ccu.umanitoba.ca (Gary Mills) (01/10/89)

In the recently-posted rs232 addition to minix-st, a completely separate
driver and kernel task is used for rs232.  I had hoped it could be combined
with the tty driver.  Aren't we trying to keep Minix small?  Is there likely
to be an "official" rs232 driver for minix-st, perhaps somewhat related to
the PC version.  Finally, the "cu" binary was uuencoded, but also archived
with a TOS program called ARC.  I would prefer if submitters would use Minix
archiving tools only, because I run minix-st, but don't have TOS.  (I recently
ported minix-st to another 68000 machine.  I had to modify all the drivers, 
and rebuild the kernel, but minix-st binaries run just fine.  I was very
impressed with the kernel code, and the port was easier than I expected.)

-Gary Mills-          -University of Manitoba-        -Winnipeg, Canada-

ast@cs.vu.nl (Andy Tanenbaum) (01/10/89)

In article <6422@louie.udel.EDU> mills@ccu.umanitoba.ca (Gary Mills) writes:
>In the recently-posted rs232 addition to minix-st, a completely separate
>driver and kernel task is used for rs232.  I had hoped it could be combined
>with the tty driver.  Aren't we trying to keep Minix small?  Is there likely
>to be an "official" rs232 driver for minix-st, perhaps somewhat related to
>the PC version.  

I still believe in small-is-beautiful, but I am increasingly alone.  But
I don't give up easily.  There will certainly not be an official RS-232
driver for the Atari from me.  If Johan decides to do one, that will be
reasonably official, but I don't think he has time now.  In practice this
means there won't be an official one for the next half year or more.

Andy Tanenbaum (ast@cs.vu.nl)

johan@nlgvax.UUCP (Johan Stevenson) (01/11/89)

In article <6422@louie.udel.EDU> mills@ccu.umanitoba.ca (Gary Mills) writes:
>In the recently-posted rs232 addition to minix-st, a completely separate
>driver and kernel task is used for rs232.  I had hoped it could be combined
>with the tty driver.  Aren't we trying to keep Minix small?  Is there likely
>to be an "official" rs232 driver for minix-st, perhaps somewhat related to
>the PC version.

Almost a year ago a student worked at Philips on the RS232 driver for
MINIX-ST based on tty.c. Since this was for a prelease of MINIX-ST it
needs minor work for the current version, but it certainly doable.
It also needs work for incorporating some stty/gtty changes from
MINIX-PC 1.3 that must be incorporated into MINIX-ST 1.1.
The rs232 driver really worked. Even Phil Karn's TCP/IP package was
ported at that time using SLIP over rs232, and we succeeded hooking it
up to either a VAX or Sun.
One issue in favor of a separate driver might be speed. We have not
done any measurements at that time, but I think it worked for 2400
baud, 4800 baud often, but not for 9600.
It is worth the effort to reconsider, but I have no time now, and
I think some others are already working on it (yes?).
In case it might help I could send someone a snapshot.
--
Johan W. Stevenson	johan@pcg.philips.nl		Philips Research