M68K for DC

[quzar]

[quote author=Hola link=board=dcemu;num=1083323639;start=345#348 date=08/27/04 at 12:33:03]I think the point DemoniusX was trying to make is we worry about perfecting emulators are perfectly good enough such a SMS instead of worrying about "more important things"[/quote]

The thing is though, this will make those still far from perfect (the emulators you are thinking of). SMS emulation is actually really really close to being completely full, moreso than the emulation of the other systems this would help with.

[Alexvrb]

Not to mention updating an SMS emulator to use a new Z80 core wouldn't exactly be an epic undertaking - not after someone else writes the core, and it becomes implemented in a couple of other emulators. I agree that SMS Plus is damn near perfect now, before it SMEG was about as good but had no saving. Still, if you can make it better thanks to an excellent new Z80 core, why not?

Of course as Meta said its still up to the coders to decide what they want to do. If nobody wanted to tinker with SMS Plus ever again, I'd be content with that decision as well.

[wraggster]

any news on the progress on the 68k cores ??

[fox68k]

Well, my 68k core is nearly completed

Interesting features available now:

- Accurate opcode timing (even MULX, for DIVX 5% inaccurate timing).
- Undocumented flag calculation (CHK instruction).

Not implemented yet:

- xBCD instructions.
- ADDX y SUBX instructions.
- Partial hardware interrupt support.
- Some API functions (set_register, fetch, peek, poke).
- Some capabilities like custom interrupt handling (for NeoCD/SDL DC).

Not tested yet:

- Roughly 40% of implemented opcodes.
- Hardware interrupt handling (some code left as i pointed above).

I have tested some little programs and it worked successfully, like the following one. It sorts a table of integers by the bubble sort algorithm:

************************************************** *******
Bubble Sort example: Numbers
************************************************** *******

absolute
org $500

zero equ $0
one equ $1

* Bubble

start lea.l e_table,A1 * End of the table
bubble lea.l table,A0 * Initialize table pointer
move.b #zero,D1 * D1 change flag

contb move.b (A0)+,D2 * One element
move.b (A0),D3 * Next element

cmp.b D2,D3 * Compare
blt greater * D3<D2
bra test * D2<=D3, do not change

greater move.l A0,D0 * \
sub.b #one,D0 * } recover the pointer
move.l D0,A0 * /
move.b D3,(A0)+ * D2>D3
move.b D2,(A0) * invert and go forward
move.b #one,D1 * Flag change
bra test

* Miramos a ver si acabamos o no
test cmpa.l A0,A1 * Compare with the end
beq endtab * Finish
bra contb * Continue with the bubble

* Changes?
endtab cmp.b #one,D1
beq bubble * There was changes, come back to start

* Program end
endp jmp endp

* Data initialation

table db 5,7,8,5,6,3,2,1,1
e_table db 0

end

I know there is not too much yet, but i hope to finish it (with all the required capabilities) within the first half of september.

Greetings.

P.D: Wraggster, it'd be nice if you post this in the front page. Thanks.

[wraggster]

nice to hear of the progress

[Hola]

Its great to know that Genesis and NeoCD will have more than enough power to be fullspeed now.

[quzar]

[quote author=Hola link=board=dcemu;num=1083323639;start=345#355 date=08/29/04 at 20:29:05]Its great to know that Genesis and NeoCD will have more than enough power to be fullspeed now.[/quote]

Dont jump to conclusions. I=There is no way of knowing how much faster the asm core will be than stef's c68k.

[Hola]

True but the new Z80 comes out and this new core is gonna be faster or so its said. So with the new Z80 and the new Sh4 there should be plenty enough power to emulate these 2 systems perfectly.

[Alexvrb]

[quote author=Hola link=board=dcemu;num=1083323639;start=345#357 date=08/30/04 at 19:46:51]True but the new Z80 comes out and this new core is gonna be faster or so its said. So with the new Z80 and the new Sh4 there should be plenty enough power to emulate these 2 systems perfectly.[/quote]
Maybe so. But what he said still holds true... you're not coding the cores or the emulators in question, so how can you automatically assume these things? Basically let's just wait and see.

[Hola]

I'd beat $50. NeoCD is already fullspeed and genesis needs about 8% more speed and a better sync on music.