M68K for DC

[WHurricane16]

To fox68k -

This scene is getting technically very interesting lately. Can't wait to see Wraggster's yearly review in 1st qtr 2k5!

[wraggster]

so is stefs 68k core asm or C?

and welcome to the Dreamcast scene

[quzar]

stefs 68k core is in C, but it is very very well written. He says that by the way it works it would be hard to get more speed by using asm. There were still a few things he wanted to do to gain a bit more speed.

[fox68k]

Wraggster ask me about core completion, so i try here to write a brief report about:

What it is implemented:

- Interface functions:

• General purpose: initialize, reset, emulate, get_pc, get_cpu_state.
  Â* Â*
• Hardware interrupt handling: raise_interrupt, lower_interrupt, get_interrupt_vector, change_interrupt_vector.
  Â* Â*
• CPU context handling: get_context_size, set_context, set_register.
  Â* Â*
• Timing: get_cycles_counter.

- Opcodes: 70% aproximately.
- Flag calculation on most of the implemented opcodes.
- Internal memory handling routines (fetch, read and write) in all data sizes.
- All addressing modes.

What it is not implemented:

- Interface functions:

• General purpose: peek, poke.
  Â* Â* Â*
• Hardware interrupt handling: None.
  Â* Â* Â*
• CPU context handling: get_context, get_register.
  Â* Â* Â*
• Timing: trip_cycles_counter, control_cycles_counter, release_timeslice, add_cycles, release_cycles.

- Hardware interrupt execution.
- Error exception (bus error, address error, privilege violation, illegal exception) handling.

And that is all. I have written the function names too to show you core interfacing at a glance.

I hope you find my report interesting. Â*

Cheers.

[wraggster]

Nice

lets hope the other great coders here team up with you

[fox68k]

me too Wraggster cause i can't wait to see all our work mixed up :

[Eric]

Okay so if this is written in sh4 asm does this mean it would help for the GBA,N64 and Saturn emus on the dreamcast?

[fox68k]

Nope, those game consoles does not have a M68k processor inside so this core won't help at all.

This emu is intented to be used in Genesis or NeoGeoCD and in a good amount of arcade machines (CPS-1 for example) emus.

[Eric]

Okay what about SNES emulators then?

[Ian_micheal]

[quote author=quzar link=board=dcemu;num=1083323639;start=270#279 date=08/01/04 at 12:31:38]I can put it into NeoCD. I first put C68k into it, so im fairly familiar with the CPU interfaces.[/quote]


Hmm if you did you never gave it to me working i worked with stefd he put the core in and to compile it needed precompiled files and 1 precompiled from me.

HLE stuff was not added when you attemped it no way it would work.

I dont want stef to read that becuase he put the core in neogeo cd and showed me the functions after that i understood it was able to get it to compile then helped him to get it to compile with some little setup problems in neogeo cd.


Stef put the core in it sent me the files which still would not compile due to some strange problems which i fixed.

I can show you how and were and what to do with the new core.

Sorry if this look mean or a reproch but stef d did it not you.

Dont mean any disrespect but if i was stef and seen your comment it would slightly piss me off.