Path: utzoo!attcan!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!AECLCR.BITNET!01659
From: 01659@AECLCR.BITNET (Greg Csullog)
Newsgroups: comp.sys.atari.st
Subject: GDOS vs G+Plus and Revolver & Spectre/PC Ditto
Message-ID: <8906090028.AA08920@ucbvax.Berkeley.EDU>
Date: 9 Jun 89 00:24:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 39

Atari programs that use GDOS write device independant output files called
metafiles. GDOS takes these files and in conjunction with nonscalable fonts
and device drivers, it maps the metafile to physical output devices like
printers and plotters. GDOS, unfortunately, slows down some GEM functions
like windows. Since GDOS has to be loaded into memory when the ST is booted
and remains in memory during a session, this speed deterioration lasts even
if you use a program that does not use GDOS. G+Plus, a third party replacement
for GDOS, overcomes the speed problem and is worth buying if you use GDOS prg
a lot (EASY DRAW, TIMEWORKS DTP, MS WORD).

When you boot and load GDOS, it looks for a file called ASSIGN.SYS that tells
GDOS where to find fonts. When you run a GDOS requiring program (like EASY DRAW)
then the fonts are loaded from the path specified by ASSIGN.SYS. Since only
one ASSIGN.SYS file is read in at boot up, all GDOS requiring programs will
share the same fonts (if you have TIMEWORKS DTP fonts specified in the
ASSIGN.SYS file then EASY DRAW will use them). G+Plus lets you choose different
ASSIGN.SYS files on boot up, GDOS does not.

Some good ST programs that use multiple fonts do not use GDOS and its fonts.
Examples are SIGNUM2, CALAMUS and PUBLISHING PARTNER (does PAGESTREAM use
GDOS fonts?)

The advantage of GDOS over POSTSCRIPT for outputs is speed. A typical page
from EASY DRAW or TIMEWORKS DTP to an SLM804 is < 60 sec. The same page to
ULTRASCRIPT, the ST's POSTSCRIPT clone, will take much longer. However, the
quality of the output will be much better with ULTRASCRIPT.

With Revolver, I can divide up my Mega's memory and run more than one appl. at
a time. Unfortunately, I can not run Spectre or PC Ditto in one partition and
GEM codes in another since both emulators cannot handle the Revlover
environment. IF THEY COULD!!!!, I could run PC codes, Mac codes and GEM codes
AT THE SAME TIME and switch between them. Too bad this cannot be done yet (if
ever) but it would be nice.

Finally, Amiga vs ST. The Amiga uses memory paging. Eveything above 512K is
not main memory but paged memory. Since the Mac needs continuous memory, the
Amiga version of a Mac emulator cannot run in more than 512K of memory.
Therefore, unlike Spectre which gives me a 1.7 meg Mac, the Amiga-Mac has
limited capability (at least that's mu understanding of the situation).