M68K for DC

[Clessy]

I didnt mean to lash out at you like that BA it's just that is so frustracting to see that you have all the parts you need to make a substacual update yet you dont have the time and no one else wants to help you out and make the next release. I mean we got sound but its only for the SGG which had offer a centered screen and only supported one game. If the sound was just added back to the orginal version which you release that would make a awsome release. I'd use it to play all my Genesis games that didnt require saving.

About the underclock chart. Would you like me to start testing with it? I mean I could test many games but as soon as you add sound those settings would become off again.

[BlackAura]

Don't worry about the Z80 or frameskip. The Z80 can't be significantly underclocked, because it'll screw the sound up on most games.

All I really need is the M68K clock speed. Basically, this value should be the minimum value before the game starts slowing down instead of speeding up. Some games need full speed, but many can get away with 200, especially the earlier games.

[Ian_micheal]

Ive put The same frameskip code into The sdl version now and centered screen. Workes a lot better then before bascaly it needs a menu. Ive got the sound working better it's inited when the frameskip happens seems to force it to synic.

Any way it does work about as well as dreamsnes but it needs a menu i never bothered with it Bacause Black aura is still working on it and he ported it first.

[Kamjin]

backtracking a bit..

Quzar,
the 68008 is a 68000 with a 8 bit data interface...
just as the 68K is a 32bit cpu with a crippled 16bit databus..
so the only thing that changes are the timings.. there's
also two packages.. one with enough address pins
to handle 1MB and the other for 4Mb I think..

as for what uses it.. arcade wise.. it's totally slipping
my mind.. but I'm staring at some chip's I've pulled out
of PCB's so something uses it????
Computer wise I think the Sinclair QL used it..

[quzar]

cool. maybe we will se some emulators for that soon then :P

[BlackAura]

[quote author=Ian_micheal link=board=dcemu;num=1083323639;start=60#72 date=05/10/04 at 07:01:43]
Ive put The same frameskip code into The sdl version now and centered screen. [/quote]

Really? I didn't think you'd seen the auto frameskip code...

[Ian_micheal]

It's an edited version of Quzar's Frameskip code From neogeo cd. If you check the sources to 6.5 you will see it. Thats were it's from And added to the SDL version of genesis plus. Works very well Sound and all on some games. Better then whats out there at the moment. Needs a menu.

[BlackAura]

Ah, I see...

The auto frameskip code I wrote allows GP to run pretty much at full speed, but with low framerate unless you start playing with the clock speeds. Personally, I think it's unplayable like that, but then again I was trying to play Sonic the Hedgehog. It's not exactly the most forgiving game when it comes to frameskipping. Rocket Knight Adventures (one of my favourite games on the Mega Drive) works pretty well. The sound is still crap (by my standards, anything less than perfect is crap), and I still need to work out a better way of handling it.

[Ian_micheal]

Yeah combine the auto frameskip , with Under clocker table for a lot of good games the sound seems to be fine to me i dont get any problems when i force it to init the same time the frameskip starts. Things blow up when they should.

Sample rate is low but it does not have sega smash pak sound it's has fm as well.

These things together it's very playable and with sound.

[Clessy]

Ian, I don't see why you can't release your newer version just because BA orginality ported it. I'm sure he wouldnt mind and i'd so like to play around with it. Did you ever add saving?