Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!pnet01.UUCP!panther
From: panther@pnet01.UUCP (The Panther!)
Newsgroups: comp.sys.apple
Subject: Re: Peripheral Card I/O
Message-ID: <8906061818.AA04977@crash.cts.com>
Date: 6 Jun 89 15:21:26 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: pnet01!pro-nsfmat!pro-lep!panther@nosc.mil
Organization: The Internet
Lines: 34

Network Comment: to #4236 by pnet01!crash!pro-nucleus.cts.com!tjohnson

I've programmed a few simple chat programs before, one for a Micromodem ][e
and a few for an external with Super Serial Card. I haven't ever used a 1200A
so this information may not apply.

As far as I can tell, you should use the Pascal entry to set it up. Otherwise,
it depends on how much you trust your card whether or not you use the
Pascal-IN and Pascal-OUT routines provided on standard cards.

I never trust the guys who make hardware. I dug in and found the Status bytes
on both modem cards and saw where it was "Receive Register" on one of the bits
of that byte. When I LDA Status  then AND #$xx (whatever the bit is for the
register) and then you BEQ xx or BNE xx depending on how the bit is set and
how the register will tell you there is a character in the buffer. When you
don't get a character in the buffer, then you check your own keyboard. If
there's something there, LDA $C000, BPL (back to check register). STA Write
register/read register. Sometimes they double as read/write in one byte.
When you do get a character then you LDA Write reg/Read reg then you print it
to your screen with either JSR $FDF0 or JSR $C307 (C307 is output for the Aux
80 column card). Then JMP to the status bit checker.

Notice how you must have a loop so you don't get stuck only waiting for input
from either keyboard or modem...Hope you can understand some of this and find
the right bytes in your firmware!

Jason Hughes
Lots of luck, I know I wish I had some help trying mine.
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