Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!ccu.umanitoba.ca!herald.usask.ca!alberta!alberta!edson!news
From: kurtk@dino (Kurt Klingbeil)
Newsgroups: comp.graphics
Subject: info sought on GML 'language'  for Bruning/ZETA plotters
Message-ID: <1991Feb14.193932.1845@ee.ualberta.ca>
Date: 14 Feb 91 19:39:32 GMT
Sender: news@ee.ualberta.ca
Organization: Univ. of Alberta
Lines: 20
Originator: kurtk@bode.ee.ualberta.ca


Bruning wants $2500 to make their ZETA8 plotter understand HPGL.
Practically nothing talks GML (except SAS), which isn't hard to understand
since from what I've been able to glean from the manual and some plot
files, GML is even more bizzarrrre than Intel.

e.g.: - numeric values use base 32 signed numbers with digits 0-7A-X
	  - the alpha/numeric/symbolic characterset contains sequences like:
	    ' ABCDEFGHI .<(+ &JKLMNOPQR!$*); ' in order from '20' - '2X'
	  - apparently, the only absolute coordinate is (0,0) i.e. the starting
		point
	  - apparently, any error in the incoming plot stream will immediately
		kill the plot (not at the offending sequence, however, but several
		commands/characters before) with no possibility of a software
		reset

I am most interested in the commands for: drawing an arc, defining/filling
a polygon, and a return-to-starting-point or move-absolute-anywhere.

thx, k^2