From: jornmoe@fredrik.atari.no (Joern Moe)
Newsgroups: comp.sys.atari.st
Organization: Atari Corp. Scand. AB (Norway)
Subject: Re: TT Compatability questions
Keywords: TT, ST, compatible, games, applications
	<1992Sep7.090500.20341@cs.hw.ac.uk> <H.R5av1hwO5UM@fredrik.atari.no>
	<1992Sep10.084347.5913@cs.hw.ac.uk>
Reply-To: jornmoe@fredrik.atari.no
X-Software: HERMES GUS 1.03 Rev. Apr 14 1992
Date: Thu, 10 Sep 1992 18:39:42 MET

In <1992Sep10.084347.5913@cs.hw.ac.uk>, Neil Forsyth writes:
----stuff deleted----
>PC's are not the same! Gawd! They've got different video cards, memory
>management, processors, mice, DOS, BIOS. In fact the use of the BIOS in PC is
>almost essential to insulate you from the various hardware configurations.
>There are some notable exceptions such as the keyboard and 'standard' video.
>
>Notice how the PC version of Speedball 2 works on loads of PC's and can be
>installed on the hard disk but the ST version does not work on the TT or
>Falcon and can't be installed on HD. Bad coding in the disk department?

Ok, I'm mistaken....

-----stuff deleted------
>Many were the best of the latest releases. The spread (if you can call it
>that :-) of games that did work dated from 1986 to the present day.
>Speedball 2 didn't work but Archipelagos did (8Mz no cache).

I don't know too many games but trying a few games on my TT somwhat validates
what you say. A very old game as the FS II does run (not quite stable but). And
the newer the game is, the biger the chance is that it doesn't run.

>Most of the speed dependant code was in the DMA routines.
>
>One of the reasons the games often crashed on the 68030 was their test for
>being in Supervisor mode. This was usually part of the copy protection.
>They used the MOVE SR,Dx instruction which on the '030 is privileged.
>They could have used the GEMDOS Super call ($20) to find that out. Strangely
>if they found they were in User mode they used Super to change. However the
>protection heavily depended on using the trace exception which caused it
>to fail on the 68030.

I wrote 'trap routines' when I should have writen 'exeption routines'....

>Another common error is to load code/data at low absolute addresses that
>flattens OS workspace. Even seven years on some programmers still do this!
>Fixing your screen memory at $78000 is also a problem. With TOS demanding
>more low memory there is the risk that programs will bang their heads on their
>own video RAM. OK that would be a bummer on a 512K machine anyway.

>>Actually we agree on the lousiness of game-writers. I do howewer think
>>that the Falcon is as ST(e) compatible as the MSTE (with cache and 
>>16MHZ on) but with additonal problems with trap's as mentioned above!
>
>Bad coding is not just the domain of the game writers. It's sad to think that
>these bad coders will hurt sales of the Falcon which so desperately needs
>software.

Yes, indeed..

>>PS. Do you have a Falcon???
>
>Maybe. I can't say. 
Why not?

>I am a developer though.

So am I. Not that I've developed much yet, but give me a Falcon.....

-- 
  _______________________________________________________
 / Joern F. Moe /  All above is my own personal opinion! \
/ Oslo, Norway /  Any lack of opinion above is also mine! \
-----------------------------------------------------------
Xref: sparky comp.sys.atari.st:13741 rec.audio:12446 sci.skeptic:16378