[Hatorijr]

well, i decided to take a swing at doing the gameboy now, though after reading about the troubles people had with it at emutalk, i know i am in for a long ride with this one but i think its possible to get something done on it, so wish me luck.

 

[fried_egg]

haha can i imagine when people get to making emulators a couple decades from now. theyre going to be making emus of dozens of generations of consoles before they get current.

 

[Hatorijr]

yea lol, i have 2 emus under my belt now, time to get working on something that is a real challenge . i already have a basic gui setup, with basic video output capability for when i actually get something to display lol.

 

[Phil]

Try for a Pcsx2 emu for a real challenge.

jk kidding good luck with the gameboy

 

[Hatorijr]

i have the first version of my opcodes finished, soon to put them all into my decoding switch and than to work on putting in timing using cycles and start work on gfx.

 

[@ruantec]

Awesome job as usual mate

 

[runawayprisoner]

We're moving fast now, aren't we? I think I'll see a PSX emu from you in a few months.

 

[Hatorijr]

well it would maybe depend on how fast i can start knocking things out with this emu, coding opcodes so far have not seemed to difficult i think really the difficult part is just timing things correctly really. though at some point i really need to look into properly using direct sound lol.

 

[Chrono Archangel]

well I started a GB emulator yesterday. I have most of the opcodes in... missing a few like push/pop/rst. Quick question, I read that the GB has a few more instructions than the 8080... anyone know what there opcodes are? And does it use some (or any) of the Z80 extended instructions. I keep reading that it is more similor to the Z80 but doesn't use any instructions from it XD

Hoping to have afew 32kB games showing garbage in a few weeks.

 

[70597]

Are you still programming it in that weird MS Office language or whatever? I forgot the name of it. :<

 

[Chrono Archangel]

its not office!
its X++ in Microsoft Dynamics AX This time around I'm pretty sure it won't be able to run it fast but I don't mind. Just want to see if I manage to get something to show.

Anyway... we'll see

 

[70597]

Sorry. I honestly forgot the name.

 

[runawayprisoner]

well I started a GB emulator yesterday. I have most of the opcodes in... missing a few like push/pop/rst. Quick question, I read that the GB has a few more instructions than the 8080... anyone know what there opcodes are? And does it use some (or any) of the Z80 extended instructions. I keep reading that it is more similor to the Z80 but doesn't use any instructions from it XD

Hoping to have afew 32kB games showing garbage in a few weeks.

It's a modified Z80 AFAIK. Anyway, here's an opcode decoder for your convenience:

Decoding Z80 Opcodes

Following that would be much faster than branching out all byte codes you can imagine... :innocent:

Note that the encoding of opcodes on the Gameboy is slightly different but only for a few opcodes. Aside from that, the rest retains their original use.

 

[Chrono Archangel]

Well I made a little progress this week. I have Tetris loading and running without it crashing. Seems it doesnt use any Z80 instructions so far because I don't have those implemented (the rot ops).

Specifications
This doc looks significantly better than what I was using so hopefully this will get me going again. need to look at graphics now to see if I can get anything to output. (but ill probably have to do flags and interrupts first XD)

 

[cottonvibes]

yeah i used that nocash website for my nes emu.
the guy wrote some good docs.

 

[Chrono Archangel]

indeed, worked on a disasm to help me debug. my flag handling isnt quite right so right now it crashes

 

[Hatorijr]

which flag you have issues with? if it is the half carry, when i worked on space invaders i figured out a great way to handle it without any real issues and space invaders works flawlessly.

 

[Hatorijr]

after quite a bit of work today i finally have something to show for my efforts since i started this project, and that being the bootstrap loads now, visually it looks ok but i have bugs that are obviously stopping much else from working. i am starting out testing with asteroids but it wont load past the boot strap for now but that will change soon i am sure .

 

[cottonvibes]

great job :thumb:

 

[Exophase]

after quite a bit of work today i finally have something to show for my efforts since i started this project, and that being the bootstrap loads now, visually it looks ok but i have bugs that are obviously stopping much else from working. i am starting out testing with asteroids but it wont load past the boot strap for now but that will change soon i am sure .

Are you remapping the first 0x100 bytes to the ROM when $FF50 is written to by the bootstrap?