news@macuni.mqcc.mq.oz (USENET News System) (11/27/90)
>In a message >> From: nugteren@pttrnl.nl > >Nils Nugteren asks: > >> I have written an interrupt handler in Think C, that catches incoming >> characters from the serial port and manipulates these in the background >> (i.e. invisible to the user). It works fine as an application, but I >> am having troubles installing it in the background (memory resident etc.). >> I'm new to MacIntosh programming so I would appreciate any help greatly. > >Nils, my serial drivers patch themselves into the level 2 dispand reprogram the SCC completely. What you are trying to do is somewhat >different so take these suggestions with a grain of salt. From: s8925188@mqcomp.mqcc.mq.OZ (Philip Craig) Path: mqcomp!s8925188 Chris has reprogrammed the SCC completely, he says above. My questions are related to this: Has anyone else done this, and how hard or easy was it to do? I am interested in running the SCC in a synchronous mode and using it's HDLC capabilities. Has anyone done this? Can you show me some source code :-) ? I am also wondering: is the complete SCC functionality still there in the later models with all the VLSI chips? I mean, the Z8530 chip seems to have gone the way of the dodo in my IIfx, is it completely emulated by Apple's replacement, or is only the functionality that Apple uses ported across? ------------------------------------------------------------------ I've got this terrible pain in all the diodes down my left side... ACSnet ( s8925188@mqcomp.mq.oz ) UUCP ( uunet!munnari!mqcomp.mq.oz!s8925188 ) Internet ( s8925188%mqcomp.mq.oz@uunet.uu.net )
urlichs@smurf.sub.org (Matthias Urlichs) (11/28/90)
In comp.sys.mac.comm, article <804@macuni.mqcc.mq.oz>,
s8925188@mqcomp.mq.oz (Philip Craig) writes:
<
< Chris has reprogrammed the SCC completely, he says above.
<
< My questions are related to this: Has anyone else done this, and how hard or
< easy was it to do? I am interested in running the SCC in a synchronous mode
< and using it's HDLC capabilities. Has anyone done this? Can you show me some
< source code :-) ?
<
Yes, I did that a couple of years ago.
My project was to implement X.25 using the SCC chip instead of a Nubus card.
That project died because Apple Germany seemed to be unable to part with the
specs of Apple's X.25 driver interface (programs written for one should run
on the other, after all).
Source code? ahem... if you want to dig through my low-level stuff, with
variable names and (few) comments in German, be my guest. :-(
A better idea would be to get the Z8530 product specs from Zilog; the
document number printed on this booklet is 00-2439-01 and the phone number is
(408)370-8000. Implementation was, as I recall, work, but not impossible.
Especially since you can use the internal clock to set the 8530's speed to
one baud or so, and watch the data in real time -- serial analyzers are
expensive.
< I am also wondering: is the complete SCC functionality still there in the later
< models with all the VLSI chips? I mean, the Z8530 chip seems to have gone the
< way of the dodo in my IIfx, is it completely emulated by Apple's replacement,
< or is only the functionality that Apple uses ported across?
It's still there, only hidden. You would have to turn on the Compatibility
Mode (there's a CDEV for this), which tells the IOProcessor to hide itself
and mimi the Z8530 at some address or other. (There are low memory globals
for this.)
--
Matthias Urlichs -- urlichs@smurf.sub.org -- urlichs@smurf.ira.uka.de /(o\
Humboldtstrasse 7 - 7500 Karlsruhe 1 - FRG -- +49+721+621127(0700-2330) \o)/