Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site joevax.UUCP
Path: utzoo!decvax!bellcore!petrus!magic!joevax!sdh
From: sdh@joevax.UUCP (The Doctor)
Newsgroups: net.micro.mac
Subject: Re: ??? PC printing of Macintosh pictures ???
Message-ID: <229@joevax.UUCP>
Date: Fri, 8-Aug-86 13:28:17 EDT
Article-I.D.: joevax.229
Posted: Fri Aug  8 13:28:17 1986
Date-Received: Sat, 9-Aug-86 10:07:06 EDT
References: <589@ssc-bee.UUCP>
Distribution: na
Organization: Bell Communications Research Inc., Morristown, NJ
Lines: 43

> For some reason (ahh, the glory of a "we done doed it") we are going to attempt
> to transfer some Macintosh pictures to a PC-XT. We thought that we might
> try to quickly transfer via serial ports (mac to xt) using kermit (only
> because its available here and works) then we wanted to try and process/print
> the picture on an Epson or HP LaserJet.
> 

What you should do is send the Macpaint pictures to the IBM in their original
format, and convert them there, and then dump them.

The format is:
The first 512 bytes are a header. You can ignore that.
What follows is packed data in the following scheme:


+------------+------------+-----~~-----+------------+
| run_length |     variable length data field       |
+------------+------------+------------+------------+

consider run_length to be a signed 8 bit integer.

if run_length >= 0, what follows is (run_length + 1) bytes of raw data
        to be copied to the ouput stream.
if run_length < 0, what follows is a single byte of repeating data to be
        copied to the output stream (1 - run_length) times.

Things to remember:
A standard MacPaint picture consists of 720 lines each containing 72
bytes.

Macintosh pixels are square.  Displaying them on an IBM monitor will
make images look stretched because of the difference in aspect ratio.
If your printer doesn't produce equally proportioned dots, you'll have to
compensate.

If you'd like, I have a utility written in AZTEC C (usuable only in the 
AZTEC shell since it needs ouput redirection) that converts the PICT type
(used in the scrapbook etc) to a hex format.  You could then send that text
to the IBM and convert it there.  It will not do an entire MacPaint picture,
to the best of my knowledge.

Steve Hawley
joevax!sdh