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WIP Atari ST ScummVM-lite

Posted: Mon Apr 13, 2020 6:26 pm
by agranlund
I've been away from Atari for a while due to work, but managed to get enough meaningful progress done on my ScummVM port to show an early WIP video. I'm thinking I could use this thread to post updates whenever there is any :)

This is not intended to be a fully featured port of ScummVM but rather much stripped down and optimized for size and performance for specific game(s) on Atari. I am treating it more like if I was porting a game to a much lesser platform, not caring much about generic and portable code or compatability with anything other than Mi2/Indy4/Dott.
(There is already a fully-featured official port of ScummVM for Atari, and I'm not intending to reinvent that particular wheel)

My end goal is to have it running Monkey Island 2 on a RAM expanded but otherwise unaccelerated 8Mhz ST.
It's still a long way to go, but since most drawing is still horribly inefficient for the target platform I do have some hope in being able to reach the goal at some point.

Anyways, Day of the Tentacle obviously run quite well on my TF534 accelerated ST, in glorious 16 color ST Low resolution 8-)

https://youtu.be/9gYjQiyDxfQ

--Anders

Re: WIP Atari ST ScummVM-lite

Posted: Mon Apr 13, 2020 6:39 pm
by exxos
Looking good :thumbup:

Re: WIP Atari ST ScummVM-lite

Posted: Mon Apr 13, 2020 7:26 pm
by agranlund
exxos wrote: Mon Apr 13, 2020 6:39 pm Looking good :thumbup:
Surprisingly good for 16 colors! :D

Re: WIP Atari ST ScummVM-lite

Posted: Mon Apr 13, 2020 10:38 pm
by kodak80
I agree that this looks brilliant and brings new games to the ST platform. :goodpost:

Re: WIP Atari ST ScummVM-lite

Posted: Tue Apr 14, 2020 7:51 am
by mikro
Not bad at all! I guess when you are finished it should be pretty straight-forward to re-add 8-bitplane graphics and make a TT/Falcon build of your optimised engine?

Re: WIP Atari ST ScummVM-lite

Posted: Wed Apr 15, 2020 9:29 am
by Smonson
Bravo! That is very impressive work!

Re: WIP Atari ST ScummVM-lite

Posted: Wed Apr 15, 2020 11:52 am
by terriblefire
Are you making use of fastram?

Re: WIP Atari ST ScummVM-lite

Posted: Wed Apr 15, 2020 9:15 pm
by agranlund
terriblefire wrote: Wed Apr 15, 2020 11:52 am Are you making use of fastram?
Absolutely! It'll use Fastram if it exists.
Only the final framebuffer is forced into ST-RAM, else the video circuit can't access it.

Programmers can use Mxalloc if they want to specify exactly which type of ram to allocate.
Or simply use malloc() which will prefer fastram if available, unless the program was flagged to only get access to ST-RAM (I assume they added that mechanism with the release of the TT as a compatability mode for programs that behave badly if loaded into and/or allocating from fastram)

Re: WIP Atari ST ScummVM-lite

Posted: Wed Apr 15, 2020 9:26 pm
by agranlund
Let there be sound! :D



I backported the midi code from current scummvm sources to my ancient codebase.
Midi-out from Atari is hooked up to midi-in on my Mac running an MT32 emulator.
Sounds fantastic!

I'd love to get my hands on a real MT32 but in the meanwhile my Mac is happy to pretend to be one :)

Not quite sure yet what to do about music for non-midi setups..
Adlib emulation and digitized sound will be too heavy for non-accelerated machines so I'm toying with the idea of driving the YM chip based on the midi notes - to at least get some kind of (crappy) music in those scenarios.
It's a problem for a much later day anyway, I'm super happy about the midi output!

Re: WIP Atari ST ScummVM-lite

Posted: Wed Apr 15, 2020 9:38 pm
by terriblefire
I'm really happy to see the TF boards enabling this sort of thing... :)