Hacking Commodore 64 VC Problems

[HowardC]

Well I don't wanna get into a huge side-topic here but....

Are tg-cd games tiny or something because when I think cd I think "100's of megs", and when I think wii I think "shouldn't make things that are 100's of megs". I'll give it a shot, but honestly I'm not that good at figuring out old console rom/cd formats.

As for the msx, the fact that it's a japaneese only release might make it hard for me to figure out, seeing as how JAP releases use different banner files and what not, and I can't speak the language.

 

[Lumstar]

TG-CD games are different from their original versions. Obviously the music is compressed, if nothing else. Otherwise they'd be too big.

 

[Da_GPer]

I was wondering if any progress has been done.

 

[FGOD]

i think wiicrazy made some progress but he is on vacation, so we need to wait... too bad this all goes above my knowledge, cause else i would have helped...

 

[Da_GPer]

I know what you mean. I started helping them in the beginning too, but they even got ahead of my knowledge too, which isnt that much due to not knowing how to code. LOL

 

[FGOD]

i really don't know how to code, i only knew how to inject roms and that is were i lost of, when they got to the snapshot and stuff...

cause that is more then i know about injecting

 

[Bo Frost]

no big progress yet.
wiicrazy is still working on it, even he´s on vacation.
he send me some snapshots to try but they didnt work on wii.

just be patient...

 

[FGOD]

hehehe, i thought so we are very patient... to bad i am not a coder and don't understand that kind of stuff

 

[bubbleboy]

My C-64 problem is that there is no C-64 emulator for the wii. My other problem is that I can't code at all, and if I could, my emu would run Horace Goes Skiing at 1/10 the speed, with frameskipping, audioskipping, non-working controllers and no sound. That's how much it would suck! 8)

 

[HowardC]

Trust me guys, being able to code has NOTHING to do with this sort of thing. I can code, but it doesn't really help me understand these wacky rom formats any better.

Mind you it's helpful as you might recognize the data formats, but what you need for this sort of thing is a hex editor with a good compare function and a butt load of time.

We are extremely fortunate in that most of the vc emulators use the exact same (or nearly the same) roms that are used on pc emulators of the same system. Generally the process involved around figuring out a vc rom format is to extract the rom, and see if it works on a pc emulator. If it does then the problem is already solved, as the roms are interchangeable. If it doesn't then you get a copy of a rom for the pc emulator of the EXACT SAME GAME, and compare it in a hex editor with the vc rom.

Again, we have been very fortunate in that all of the vc roms so far have had at least a recognizable chunk of data somewhere if they are different, giving a starting point to figure things out. The neogeo has been the hardest so far and from what I've followed, they guys the cracked that one did an amazing amount of work to get it working. Unfortunately, the c-64, at least to me, at first glance, is even more complex.

 

[WiiCrazy]

Update!
I have both good and bad news, good news is ik+ snapshot now loads and plays in my custom frodo without change in the snapshot itself. Bad news is I am not near my wii so I can't test and tweak it to work.

Especially for Bo Frost and for everyone else, here is my custom frodo : http://www.tepetaklak.com/data/modfrodo.rar

You can use this to save and load ik+ like snapshots.

There are yet some parts in the wii snapshot that I don't know what's for, probably the snapshots saved from my custom frodo will not work, still I think I can figure the thing out when I get back home.

ps: probably because of a possible compilation/linking problem the sound doesn't work in the emu.

 

[Bo Frost]

i tried all my original wii snapshots and the only one thats working fine is international karate.
here is what i get when trying to load those snaps in the custom frodo:

-paradroid,international karate+ and nebulus dont work. frodo just closes.
-uridium shows error "error reading snapshot file"
-california games shows error "illegal opcode 02 at 0a70. press ok to reset." after that, i see some colored blocks and then frodo resets.
-the last ninja 1 shows error "illegal opcode 52 at 64af" and rest the same as cg.

-impossible mission first starts, then tries to load from floppy(!) ,8 and then drops to c64 prompt(ready with blinking cursor). the led of the emulated floppy device blinks, like it does on "file not found".
here we can see that either the disk image is used too for this game or its one of the other files that come with this game, that the emu attempts to load.
for impossible mission, there are 3 files beside the snapshot and disk image which are between 1 to 6 kb big.

 

[WiiCrazy]

i tried all my original wii snapshots and the only one thats working fine is international karate.
here is what i get when trying to load those snaps in the custom frodo:

-paradroid,international karate+ and nebulus dont work. frodo just closes.
-uridium shows error "error reading snapshot file"
-california games shows error "illegal opcode 02 at 0a70. press ok to reset." after that, i see some colored blocks and then frodo resets.
-the last ninja 1 shows error "illegal opcode 52 at 64af" and rest the same as cg.

-impossible mission first starts, then tries to load from floppy(!) ,8 and then drops to c64 prompt(ready with blinking cursor). the led of the emulated floppy device blinks, like it does on "file not found".
here we can see that either the disk image is used too for this game or its one of the other files that come with this game, that the emu attempts to load.
for impossible mission, there are 3 files beside the snapshot and disk image which are between 1 to 6 kb big.

Well it's normal, it's based on the ik+ (or is it just ik?) snapshot file. It seems that there are a few snapshot formats. I just saw two of them for now, one of them is ik+ and the other one is california games.

Here is what I do when loading wii snapshot (ik+),
skip first 8 bytes, load the vic state (swapping hi/low bytes for integer values), load sid state, dismiss cia state, load cpu state(swapping hi/low bytes for integer values), dismiss 92 bytes, load 64k ram, load color ram, skip 1541 ram (2k)

Well IK+ is a single file game so it doesn't do disk access. Hence my custom frodo won't load snapshots that rely on 1541 (c64 drive) state. IK+ snapshot doesn't seem to be containing the 1541 state so for disk based games another host should be analyzed and used.

I believe I can tweak saved snapshot from my custom frodo to work on wii.

What I need is to identify those 8 bytes in the header of the snapshot file, reveal those 92 bytes after the cpu state... And for all that I actually only need a clean c64 prompt snapshot taken from the wii. Then I could compare it with the frodo one and can identify parts.

By the way did you have the chance to load another game in my custom frodo, save snapshot and try on wii?

 

[Bo Frost]

i tried several times to load any disk image with custom frodo but it didn´t work. it´s simply not loading. maybe somethings wrong with floppy emulation?

btw. yes, its the game ik we were talking about all the time. ik = 2 fighters, ik+ = 3 fighters

 

[Bo Frost]

somehow i got it now.i made 2 snapshots and "injected" them.both crash the wii with black screen.

 

[WiiCrazy]

somehow i got it now.i made 2 snapshots and "injected" them.both crash the wii with black screen.

I'm returning home on tuesday morning, hopefully I can get my hands dirty on my wii, clearing things up. By the way you once said you got a wad that makes you return to the c64 basic prompt. What happens when you go back to the wii menu, when you go back to game do you start where you left off in the c64 basic prompt? If snapshot saving in the emu work there, then we can get a clean snapshot from the nand of the wii. And that snapshot could be used to dig into those unrevealed bytes. If we set those bytes correctly then I think games will load without problems.

 

[Bo Frost]

By the way you once said you got a wad that makes you return to the c64 basic prompt. What happens when you go back to the wii menu, when you go back to game do you start where you left off in the c64 basic prompt? If snapshot saving in the emu work there, then we can get a clean snapshot from the nand of the wii.

you mean what happens when i reset the game? the basic prompt resets too. but it´s not like the pc version of frodo where you can load anything or take snapshots. ist just a plain c64 screen. if it is a port of frodo, it´s very customized for the wii.

 

[WiiCrazy]

By the way you once said you got a wad that makes you return to the c64 basic prompt. What happens when you go back to the wii menu, when you go back to game do you start where you left off in the c64 basic prompt? If snapshot saving in the emu work there, then we can get a clean snapshot from the nand of the wii.

you mean what happens when i reset the game? the basic prompt resets too. but it´s not like the pc version of frodo where you can load anything or take snapshots. ist just a plain c64 screen. if it is a port of frodo, it´s very customized for the wii.

Well I mean if it's in basic prompt and you write some characters to the screen do you see them at the next launch of the game? (Not resetting, going to system menu and starting te game again)
So the actual question is, in that state does the snapshot saving of the emu works? I have an ntsc wii so I'm not sure I can get through snapshot saving in the emu, as far as I remember it was crashing on return to system menu.

By the way I'm home, I'll take another approach for my first test, I'll just replace the cpu state and ram state of the ik snapshot. That way I think there is much chance for the final snapshot to work on wii. I'll update this post when I'm done with adding the feature to the custom frodo.

 

[WiiCrazy]

Yay! It worked!

Finally giana sisters on my wii, yet I regret I didn't buy a PAL wii

I'll publish the binary when I get a quick readme written and of course the instructions in my custom frodo.

 

[Bo Frost]

Yay! It worked!

Finally giana sisters on my wii, yet I regret I didn't buy a PAL wii

I'll publish the binary when I get a quick readme written and of course the instructions in my custom frodo.

very cool, that´s what i waited for. i already made a channel for giana.

congratulations!