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- Path: sparky!uunet!mcsun!sunic!aun.uninett.no!nuug!fredrik.atari.no!jornmoe
- From: jornmoe@fredrik.atari.no (Joern Moe)
- Newsgroups: comp.sys.atari.st
- Message-ID: <H.R5av1hwO5UM@fredrik.atari.no>
- Organization: Atari Corp. Scand. AB (Norway)
- Subject: Re: TT Compatability questions
- Keywords: TT, ST, compatible, games, applications
- References: <H.MGgdbM2U5VY@fredrik.atari.no>
- <1992Sep3.115337.3528@cs.hw.ac.uk> <H.2jCeQ8EYz7o@fredrik.atari.no>
- <1992Sep7.090500.20341@cs.hw.ac.uk>
- Reply-To: jornmoe@fredrik.atari.no
- X-Software: HERMES GUS 1.03 Rev. Apr 14 1992
- Date: Tue, 08 Sep 1992 20:36:36 MET
- Lines: 70
-
- In <1992Sep7.090500.20341@cs.hw.ac.uk>, Neil Forsyth writes:
- >The hardware addresses in the ST, TT and Falcon are the same (additional
- >features being an exception). The MMU is programmed to map $FFxxxxxx to
- >$00xxxxxx so there is no problem.
-
- On the TT, this is not the case. Several TT spesific hardware and RAM is in
- the area above $00xxxxxx. Some games uses the highest byte in the address
- registers, and on the TT this really f***s things up! In the Falcon, there is
- NOTHING above the $00xxxxxx area, so whatever is in the high BYTE, will never
- even go to the MMU, and hence is never decoded!! THIS fact is one of the
- reasons that the Falcon should be more (M)ST(E) compatible than the TT.
-
- >My 'game code' works on all machines why can't others?
- Good for you, but sad to say, not many make 'clean' code!!
-
- >If a programmer sticks to Atari's developer guidelines then *ALL* Atari
- >680x0 machines are compatible.
- >
- I agree! But given the limited (compared to the current standards) power of the
- ST, you often have to do dirty trics to get the speed you want....
-
- >>Third, the falcon is a consumer product, the TT is not! This beeing a fact
- >>makes it obvious why Falcon has to be more 'old-ST-games' compatible than
- >>the TT was.
- >
- >I view the TT as being to the ST what 486DX-33 PC's are to 386SX-16 PC's.
- >They are every bit as commercial. If you buy a PC game these days you can bet
- >it will work on any PC. This should be true of ST games on the Falcon.
-
- This comparison is not good! The only difference between 486DX PC's and
- 386SX PC's is the processor. The rest of the machine is the same! The ST is a
- machine designed as a keyboard home-computer. The TT is based upon the hardware
- of the ST, but have essential additions to make it more 'business'-oriented.
- Like internal harddisk, VME-bus, SCSI-bus, higher resolutions, LAN port etc.
-
-
- >Most of the games that don't work with faster processors and caches are
- >written by f*ckwits that go straight for the DMA/FDC hardware directly. This
- >is because their software timing loops get shortened. Why didn't they use
- >the BIOS or even XBIOS calls?
- >Atari are now recommending that Falcon (and I guess ST) games work on hard
- >disk and use copy protection based on word entry from a manual.
- >
- >To sum up, I have tried running a *LOT* of ST games on a Falcon and less than
- >10% of them worked. This is one reason I think the Falcon will fail if markted
- >as a games machine. The available leisure software will be small.
-
- Only 10%? Wether this is bad or not depends uppon the quality of these games!
-
- >Only a couple of the games worked after disabling the cache and setting
- >the speed to 8Mz. Since most games that load from a bootsector and don't use
- >system calls failed I assume that they were not 68030 compatible.
- There is only two things a programmer can do which a proper written trap-
- handler on the 68030 can't handle to make it 100% compatible (with cache off).
- Those things are speed depended code and self writen trap routines!!
-
- >Atari were not to blame for these incompatibilities however I do blame them
- >for not kicking butt when the TT didn't run software. Programmers should have
- >learned their lesson back then.
-
- 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 cahe and
- 16MHZ on) but with additonal problems with trap's as mentioned above!
-
- PS. Do you have a Falcon???
- --
- _______________________________________________________
- / Joern F. Moe / All above is my own personal opinion! \
- / Oslo, Norway / Any lack of opinion above is also mine! \
- -----------------------------------------------------------
-