Path: utzoo!utgpu!watmath!orchid!rbharding
From: rbharding@orchid.waterloo.edu (Ron Harding)
Newsgroups: comp.sys.atari.8bit
Subject: Parallel Printer interface
Summary: ATASCII - ASCII conversion
Message-ID: <682@orchid.waterloo.edu>
Date: 7 Apr 89 19:31:40 GMT
References: <8904071504.AA22717@ucbvax.Berkeley.EDU>
Reply-To: rbharding@orchid.waterloo.edu (Ron Harding)
Organization: U. of Waterloo, Ontario
Lines: 24


   I was wondering about how Atari printer interfaces, or the P: driver handle
conversion of ATASCII to ASCII.  It seems to me that if the ATASCII codes such
as EOL (155, $9b) are universally converted to the ASCII codes, such as CR/LF
(13,10 $0d$0a), then important things like dot-matrix graphics will be munged
up.  But if they aren't converted, then normal text won't print properly.

   How is this resolved?  My theory is the following:

- The P: handler will perform conversion of ATASCII to ASCII if the output
command is PUT_RECORD.  This command is line-oriented (a record is always
terminated by an ATASCII EOL (155) ).

- If the output command is a PUT_BYTES, the P: handler performs no conversion
whatsoever, so graphics dumps will work correctly.

   Am I reasonably close to the truth here?  I need to know, since I am faced 
with the task of writing a P: driver for the parallel port I built for my old-
style 800.  Currently, I use a cludgy SpartaDOS program I whipped up:
      PPRINT fname.ext

   Thanks in advance.

                                Ron Harding