Path: utzoo!mnetor!uunet!cbmvax!rutgers!cmcl2!brl-adm!umd5!ames!pasteur!ucbvax!WATDCS.BITNET!DMIHOCKA
From: DMIHOCKA@WATDCS.BITNET (D Mihocka)
Newsgroups: comp.sys.atari.st
Subject: (none)
Message-ID: <8802152132.AA06812@ucbvax.Berkeley.EDU>
Date: 15 Feb 88 18:56:53 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 36

i
To Darin Wayrynen: Re: redirecting output

Yes, it can be done. First though, what does your ASL do? I helped develop
a PD program called ASL which is a super fast (as fast as TEMPUS) file
viewer/printer. It used a set of custom text plotting routines that printed
about 20,000 characters per second. I originally used them in the 8 bit
emulator, and adapted the routines to replace TOS's Bconout routine.
Fortunately, Bconout uses a vector (at $484 I _think, I'd have to look it
up) which points to the character output routine. This is done because during
ESC sequence processing, the VT52 emulator redirects the routine. This is
an easy hook, not requiring you to hook into the TRAP 13 vector, which would
slightly slow down all TRAP 13 calls. Anyway, it worked like a charm.
Listing files from the desktop was considerably faster, but Atari has since
managed to speed up the Bconout routine in the Mega to about the same speed.
If you have a Mega, it's not really worth the trouble to do this, since
you will probably get no speed increase. The problem is that when the routine
is being called a character at a time, the overhead of the TRAP eats up most
of the time. If you are doing from within your own program though, there
is a much greater speedup since yo can call the routine with a JSR instead
of a TRAP.
One thing I didn't try which would work, is to hook the TRAP 13 vector, and
check for the Cconws command. Printing strings of text at a time will get
you closer to the 20,000 chars/sec speed.
Unfortunately, I no longer have the source code to the Bconout replacer.
I only took about an hour to write in Megamax C, and as since mutated into
another program of mine.
But like I said, it can be done, and only takes about an hour to write the
entire program from scratch.

- Darek

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