11 replies to this topic

[Orion4874]

DSx86 is a dos emulator for the NDS. It is actively being updated by the author, Patrick Aalto. While the project itself is closed source(at least I don't think anyone has asked him for the source), the source code for his AdLib emulation is available. http://dsx86.patrickaalto.com/
Would this help to improve our port of dosbox or even a new dos emulator? This doesn't necessarily mean for the Wiz specifically, maybe the Pandora version could benefit as well?

DSx86 has very high compatability considering the hardware it's used on. http://dsx86compatibility.pbworks.com/w/page/26738915/Compatibility%20List

[HunterZ]

Comments from the Adlib emulator source:

@ This is my ARM ASM optimized version of the original "fmopl.c"
@ AdLib emulation C source code (as found in the DOSBox source
@ code), which had the following copyright statements:
@
@ File: fmopl.c - software implementation of FM sound generator
@                                            types OPL and OPL2
@
@ Copyright © 2002,2003 Jarek Burczynski (bujar at mame dot net)
@ Copyright © 1999,2000 Tatsuyuki Satoh , MultiArcadeMachineEmulator development
@
@ This code only emulates a single OPL2 FM sound generator, as
@ found in the original AdLib card. I hope the code has enough
@ comments so you can figure out how it works, if you are interested.
@ The main changes between this code and the original "fmopl.c"
@ code is that I tried to precalculate and move away from the inner
@ loops all possible code, sometimes at the expense of accuracy.
@
@ Efficiency has been my primary goal, accuracy is secondary.
@ Currently I believe this code uses about 60% of the ARM7 CPU
@ power to run all 9 AdLib channels.

[Orion4874]

So I'm guessing this wouldn't really help at all huh? Oh well, maybe he'll release the full source code at some point.

[HunterZ]

It might help if you're looking to get a less CPU-intensive Adlib emulation and are willing to sacrifice some accuracy to get it.

Also, I think fmopl.c might be the old core that DOSBox has recently ditched in favor of the Adlib emulation core that ScummVM uses.

[Pickle]

It might help if you're looking to get a less CPU-intensive Adlib emulation and are willing to sacrifice some accuracy to get it.

Also, I think fmopl.c might be the old core that DOSBox has recently ditched in favor of the Adlib emulation core that ScummVM uses.

your right, dosbox does not use fmopl.c anymore it was replaced by a faster implementation.

[fusion_power]

Wow, I never had thought that a NDS is powerful enough for a DOS Emulator, especilay not when you look how slow DosBox actualy is, even on modern PC's.
I guess these guys really dug deep into the Hardware to speed up Dos Emulation on such a slow system. Exactly what we need for the Pandora, how many MHz has a NDS? I guess not even close to the 600+ MHz of our Pandora.

EDIT: the compatibility list is indeed incredible! Stunt Island, my fav. DOS Game back then works on a tiny little NDS!?! Wow, this really is lightyears over that what DOSBOX can offer us, I'm jealous. ^^

So this is the difference between an accurate and an optimized Emulator, really impressive. I already see me playing Dungeon Keeper with an equal optimized Emulator on my Pandora. So, who wants to code such a thing?

Edited by fusion_power, 28 September 2011 - 01:07 AM.

[HunterZ]

Ought to get the DSx86 author to sign on for open handheld ports, as they seem to all be using ARM processors.

[jmetal88]

Dude, it's written by Patrick Aalto? That's awesome! I have an old DOS game he wrote back in the day, Line Wars. I remember e-mailing him one time to ask for an EGA driver (since the game documentation said there was one available for those without VGA graphics). His reply to me was that the advertised driver had been abandoned before finishing development since EGA graphics were all but gone at the time the game came out.

[Pickle]

Dude, it's written by Patrick Aalto? That's awesome! I have an old DOS game he wrote back in the day, Line Wars. I remember e-mailing him one time to ask for an EGA driver (since the game documentation said there was one available for those without VGA graphics). His reply to me was that the advertised driver had been abandoned before finishing development since EGA graphics were all but gone at the time the game came out.

In fact he used that game in the early development of the emulator.

[quasist]

As far as I know author of that emulator said that he is busy, want finish some great features on DS, but is intrigued by awesome Caanoo processor

http://wiz.rusbase.net/forum/viewtopic.php?p=2533

Edited by quasist, 28 September 2011 - 01:49 PM.

[jmetal88]

Dude, it's written by Patrick Aalto? That's awesome! I have an old DOS game he wrote back in the day, Line Wars. I remember e-mailing him one time to ask for an EGA driver (since the game documentation said there was one available for those without VGA graphics). His reply to me was that the advertised driver had been abandoned before finishing development since EGA graphics were all but gone at the time the game came out.

In fact he used that game in the early development of the emulator.

Awesome. I have to correct myself, though. I don't have Line Wars, I have Line Wars II.

[jmetal88]

I just e-mailed Patrick. He says he is interested in the GPH consoles and doing a port, but that if he does do a port, it will probably be a long time before he gets to it. He doesn't own a GPH console at the moment, either, which is one reason he can't start on it soon. The other reason is he wants to get DS2x86 significantly improved before he works on porting anything he's been working on.