POWERPC 750CXe

[CyZyco]

I've studied the powerpc(gamecube processor) architeture and would like to do emulator to this processor in c++ anyone has courage and would like to join this project or any information to help me?

[el_pajero]

I dont know ask the moderators or the administrator

[Vegetable]

el_pajero, please do not post things like that, they are not helpful, and VERY VERY annoying. If you can't submit, don't post.

[Azimer]

IBM has public documentation available... The cube's processor has added hardware to the processor and you will find that information in the illegal Gamecube SDK floating around somewhere. Please don't ask for it in here. That is equivalent to asking for illegal ROM images.

[Marce1991]

is it to hard to program a snes emu i dont know i maybe will study a bit of C++

[CyZyco]

I already have the IBM specs to PPC and I'm get the dolwin source. I'm codind too to run in linux and windows.

[LXS]

I might be wrong but GC's CPU is a PowerPC 970 (customized), isn't it?

[CyZyco]

I might be wrong but GC's CPU is a PowerPC 970 (customized), isn't it?

I've read that it seems a 750CXe.(www.gc-linux.org)

[LXS]

I've read that it seems a 750CXe.(www.gc-linux.org)

Yes, I don't know why I said this, I've translated some docs for them :)

[Cyberman]

There is also the issue of the custom opcodes Nintendo used for 'media enhancement'. Nintendo loves proprietary. I wonder if there ever will be a game system that uses more than a standard as a gimick ;)

I suppose dolwin is a good start, however I recomend making documentation your first priority, condense it and make sure it makes sense. Then code it test it see if it works and try again if it does. People are still discovering things about the N64 now.

Cyb

[Niggy G]

There is also the issue of the custom opcodes Nintendo used for 'media enhancement'. Nintendo loves proprietary. I wonder if there ever will be a game system that uses more than a standard as a gimick ;)

I suppose dolwin is a good start, however I recomend making documentation your first priority, condense it and make sure it makes sense. Then code it test it see if it works and try again if it does. People are still discovering things about the N64 now.

Cyb

Can I ask, what exactly are opcodes? - I have a very basic understanding but its a little blury.

[euphoria]

opcodes are the only things processor can do (or what you can make it do). typically these include:
MOV (move data register->memory, mem->reg, reg->reg - move)
ADD (reg+immediate data->register, like R1=R2+3 - addition)
MUL (reg*reg->reg, R1=R2*R3 - multiply)

You get the idea. All things your computer does is composed out of opcodes. Normally there are >100 opcodes to a processor.

[LXS]

As euphoria said, opcodes *are* the language machine and there's one code for each instruction that the processor can do.
In x86 asm for example, NOP (No OPeration)instruction is 0x90. And this value is written "directly" to the processor when a NOP is requested.

[Niggy G]

As euphoria said, opcodes *are* the language machine and there's one code for each instruction that the processor can do.
In x86 asm for example, NOP (No OPeration)instruction is 0x90. And this value is written "directly" to the processor when a NOP is requested.

So the opcodes are really the instriction set? - i.e Intel and AMD use different ones?

[euphoria]

So the opcodes are really the instriction set? - i.e Intel and AMD use different ones?

No, Intel and AMD both uses the same x86 instruction set and both has the same opcodes, although there might be some differences on rarely used opcodes. If they used different intruction sets then they wouldn't be compatible.
But the SIMD-instruction sets differ, so that 3DNow!, SSE, MMX are completely different "additions" to the x86 instruction set.

opcode = instruction -> opcodes as whole are instruction set :)

[Niggy G]

No, Intel and AMD both uses the same x86 instruction set and both has the same opcodes, although there might be some differences on rarely used opcodes. If they used different intruction sets then they wouldn't be compatible.
But the SIMD-instruction sets differ, so that 3DNow!, SSE, MMX are completely different "additions" to the x86 instruction set.

opcode = instruction -> opcodes as whole are instruction set :)

I see, cheers clearing that up for me, :)

[CyZyco]

Instruction Example:
addic Intruction -0x30000000h : PPC,Gekko
Add Immediate Carrying

addic rD,rA,SIMM
rD ← (rA) + EXTS(SIMM)

0.....5 6.........1011...........1516.........31
OPCD____D________A_______SIMM

rD -> destiny register
OPCD ->opcode (addic is 12 )
rA-> A register
SIMM-> sing int imediate

[RomCal]

I would help if i had any programming skills.Sorry

[Doomulation]

Meh. Emulating stuff is always fun, but I'm not sure I'd be able to emulate a processor. Never done anything such before. Prolly advanced :P
If I could learn or something I'd really be intrested in trying to emulate a cpu.