20 replies to this topic

[eegad]

I've had Stella from long ago for when I want to occasionally play Adventure or something while on the PC. I just upgraded to the latest version (after about 5 years), and see that Stella now has the ability to store cheat codes in a 'stella.cht' file. That sounds great....except that so far I haven't been able to find a cheat file anywhere online for it. Anybody happen to know where I can get one? (I've found random, individual cheat codes to enter, but surely there must be a larger collection of codes already in a 'stella.cht' file)

[stephena]

eegad, on Mon Sep 29, 2008 3:50 PM, said:

I've had Stella from long ago for when I want to occasionally play Adventure or something while on the PC. I just upgraded to the latest version (after about 5 years), and see that Stella now has the ability to store cheat codes in a 'stella.cht' file. That sounds great....except that so far I haven't been able to find a cheat file anywhere online for it. Anybody happen to know where I can get one? (I've found random, individual cheat codes to enter, but surely there must be a larger collection of codes already in a 'stella.cht' file)

AFAIK, nobody has created a comprehensive stella.cht file. The feature has been present in Stella for several years now, but I assume most people aren't using it (or Stella) enough to generate such a file. I was planning to create such a file at some point, but I never seem to have enough time.

Edited by stephena, Mon Sep 29, 2008 2:59 PM.

[Luc]

I have a personal file with some cheats - if anyone wants to convert this into a cht file or add his own cheats, please do!

Here's what I have collected so far:


Road Runner:
lives in $c4 (sbc instruction at $fcad)

H.E.R.O.:
dynamite in $b2, lives in $b3

Kangaroo:
lives in $ad (inc $ad at $f06e, dec $ad at $f0cd)

Jungle Hunt:
lives in $88
time in $86, $87
number of boulders in $c6

Frostbite:
time in $e5
lives in $cc

Kung Fu Master:
Time in $9B, $9C
Lives in $9D (dec $9d,x)

Montezuma's Revenge:
Objects are stored in $c2 like this:

128 64 32 16 8 4 2 1
lamp sword sword key key key key hammer

Asterix:
# of objects in $c2

Donkey Kong Jr.
Lives in $93

Amidar:
score in $d9, $da, $db (anyone knows where the lives counter is??)

Galaxian:
lives in $b9
level in $af

Mario Bros:
lives in $87
bonus counter in $f2
level in $85

Night Driver:
timer in $b3
score in $b4

Haunted House:
number of matches in $82
lives in $96

Jr. Pacman
Maze in $f6 (0-6, any other number will scramble the maze)
Lives in $ff

[Random Terrain]

stephena, on Mon Sep 29, 2008 3:59 PM, said:

AFAIK, nobody has created a comprehensive stella.cht file. The feature has been present in Stella for several years now, but I assume most people aren't using it (or Stella) enough to generate such a file. I was planning to create such a file at some point, but I never seem to have enough time.

For those who have the time to go to the Stella folder and figure out which file in the doc folder they should look at, it's not clear how to find cheats for a game, so that might be one of the problems:

Quote

14. Cheatcode Manager

Stella 2.0 contains support for Bob Colbert's Cheetah cheat codes, as well as an extended Stella-specific type of cheat code that works on bankswitched ROMs.

To add/remove/edit a cheat code, enter the 'Cheat Code' dialog:

Currently, there are three types of cheatcodes available, all of which must be entered in hexidecimal format:

• Per-frame RAM cheats:

Evaluated each frame, and apply to RAM only. Format as follows:
4-digit code: c041
c0 = address
41 = data

• Cheetah codes, which are explained in detail on Bob Colbert's web page, along with a list of codes for various games. Cheetah codes don't support bankswitched ROMs, so they only work for 2K or 4K ROMs. Format as follows:

6-digit (cheetah) code: aaaddc
aaa = address - $f000
dd = data
c = count - 1

• Stella extended cheats are similar to Cheetah codes, except that they can be 7 or 8 digits long, with the extra digits used for the bank number:

7-digit (stella) code: baaaddc
b = bank (0 to $f)
aaa = address - $f000
dd = data
c = count - 1

8-digit (stella) code: bbaaaddc
bb = bank (0 to $ff)
aaa = address - $f000
dd = data
c = count - 1

There's also the concept of one shot codes. These codes work exactly the same as above, except they aren't saved. They are evaluated once and immediately discarded.

Here are a few cheat codes we've found:

Pitfall (standard Cheetah codes):

5b0ea1 - infinite lives
723ea1 - infinite time
aa5??0 - set starting level, ?? = 01 to ff (d0 is kinda neat)

Battlezone (Stella extended codes):

1236ea1 - infinite lives

Ms Pac-Man (Stella extended codes):

108fea1 - infinite lives

Does the user go Googling for a cheat tutorial or do they randomly type things into the cheat box and hope for the best? So they probably think "that looks like it's more trouble than it's worth. Some nerd living in his mother's basement will probably put together a cheat file anyway, so I'll just wait until that happens and it's included with Stella so I can just select a cheat from a list."

[stephena]

Random Terrain, on Tue Sep 30, 2008 4:45 AM, said:

Does the user go Googling for a cheat tutorial or do they randomly type things into the cheat box and hope for the best? So they probably think "that looks like it's more trouble than it's worth. Some nerd living in his mother's basement will probably put together a cheat file anyway, so I'll just wait until that happens and it's included with Stella so I can just select a cheat from a list."

Well, unless some other people start contributing their cheats, then the 'some nerd' is me, and my time is very limited as it is, so it may never happen. Remember, the project doesn't exist in a vacuum; the more people that contribute, the better that Stella will get.

And speaking of contributions, one doesn't have to send me an actual cheat file. Making the cheat file is ridiculously easy; it's determining the address(es) to modify that's difficult. So if others could send info like 'Luc', it would make it much easier on me.

[Nukey Shay]

Maybe a sticky thread should be created where such addresses can be posted. Those of us that work with disassemblies already have such contributions (figuring out score/lives is often the first step in decyphering the program).

[atari2600land]

I don't know if this is any help to anyone, but here goes:
Atari 2600 Land - Cheat section

[eegad]

Well, it's almost 2 years since I first asked, so I thought I'd follow-up...

Does anyone yet know of a stella.cht file that been posted anywhere with cheats for a decent number of games? Seems odd to me that you can easily find cheat database files for MAME, but none seem to exist for the Stella. When it was a new feature in Stella I figured, okay it'll take a while for people to figure things out and post them....but I've yet to stumbled across a cheat file. Hmmmmm.

[Luc]

eegad, on Wed May 12, 2010 6:15 PM, said:

Well, it's almost 2 years since I first asked, so I thought I'd follow-up...

Does anyone yet know of a stella.cht file that been posted anywhere with cheats for a decent number of games? Seems odd to me that you can easily find cheat database files for MAME, but none seem to exist for the Stella. When it was a new feature in Stella I figured, okay it'll take a while for people to figure things out and post them....but I've yet to stumbled across a cheat file. Hmmmmm.

I always enter my cheats directly in the debugger. I tried to make a cht file once, but I ran into some problems. I'd be willing to give it another try, if someone (stephena, are you reading?) could explain how to change more than one address in a cheat? I mean, if I wanted to write A9 00 (or EA EA EA) to 18DF and 18E0, I would have to use two cheat codes. Surely this can be done in another way, something like

bbaaaad1d2d3:0

(bb=bank, aaaa=address to start writing, d1d2d3 etc. = consecutive values to write until colon is reached, :0 = off, :1= on)

Also, the option to turn cheats on or off doesn't always work. For example, if you use the code 53EEA1 in Pac-Man to get unlimited lives, the cheat sometimes works when starting Stella - even when it's turned off.

If we could get a good working cheat editor that allows me to write more than one value, I promise to make a biiig cht file.

[stephena]

Luc, on Thu May 13, 2010 2:56 AM, said:

eegad, on Wed May 12, 2010 6:15 PM, said:

Well, it's almost 2 years since I first asked, so I thought I'd follow-up...

Does anyone yet know of a stella.cht file that been posted anywhere with cheats for a decent number of games? Seems odd to me that you can easily find cheat database files for MAME, but none seem to exist for the Stella. When it was a new feature in Stella I figured, okay it'll take a while for people to figure things out and post them....but I've yet to stumbled across a cheat file. Hmmmmm.

I always enter my cheats directly in the debugger. I tried to make a cht file once, but I ran into some problems. I'd be willing to give it another try, if someone (stephena, are you reading?) could explain how to change more than one address in a cheat? I mean, if I wanted to write A9 00 (or EA EA EA) to 18DF and 18E0, I would have to use two cheat codes. Surely this can be done in another way, something like

bbaaaad1d2d3:0

(bb=bank, aaaa=address to start writing, d1d2d3 etc. = consecutive values to write until colon is reached, :0 = off, :1= on)

Also, the option to turn cheats on or off doesn't always work. For example, if you use the code 53EEA1 in Pac-Man to get unlimited lives, the cheat sometimes works when starting Stella - even when it's turned off.

If we could get a good working cheat editor that allows me to write more than one value, I promise to make a biiig cht file.

It's not surprising that there are still some bugs in the cheatcode stuff. It hasn't been well tested, since based on very limited feedback I assumed that there was little interest. The bugs aren't huge, and I'm sure they could be squashed fairly quickly. But it would mean (a) me finding time to work on it, and more importantly (b) having someone to bounce ideas and testing to. Maybe that could be you. Be careful when asking for better features; you could be volunteering to be the test guinea pig Seriously though, this area of Stella won't improve unless/until I get more feedback.

[Luc]

Quote

It's not surprising that there are still some bugs in the cheatcode stuff. It hasn't been well tested, since based on very limited feedback I assumed that there was little interest. The bugs aren't huge, and I'm sure they could be squashed fairly quickly. But it would mean (a) me finding time to work on it, and more importantly (b) having someone to bounce ideas and testing to. Maybe that could be you. Be careful when asking for better features; you could be volunteering to be the test guinea pig Seriously though, this area of Stella won't improve unless/until I get more feedback.

I think it's strange too that there's so little interest in cheat codes. I've always loved cheating (in video games, that is). So I wouldn't mind compiling and testing a cht file for Stella, if you can find the time to fix these issues:

- Codes are applied even when turned off

- Pac-Man sometimes crashes when using Bob Colbert's codes (53EEA1 - Unlimited lives, 516EA3 - Power Pills last forever, 5E4EA1 - Able to eat ghosts at any time). Perhaps the codes are faulty; I haven't figured out yet which one (or which combination) is causing the crash. Sometimes it happens, sometimes it doesn't.

- As for the code and its parameters, may I suggest something like:

1. read bank number
2. read address (aaaa) to write to
3. read next value (dd)
4. if value = "&" go to 1 ; a different code coming up
5. if value = "#" then stop
6. write value to address; increase address by 1 and go back to 3

This would make it possible to write multiple values to different addresses in different banks, all in one line of cheat code. It could even be used to make small graphical changes in games.

Btw, thank you for adding the disable sprite collision to your latest version. It works great; I'm having lots of fun with it.

Edited by Luc, Sun May 16, 2010 1:53 AM.

[stephena]

Luc, on Sun May 16, 2010 1:50 AM, said:

Quote

It's not surprising that there are still some bugs in the cheatcode stuff. It hasn't been well tested, since based on very limited feedback I assumed that there was little interest. The bugs aren't huge, and I'm sure they could be squashed fairly quickly. But it would mean (a) me finding time to work on it, and more importantly (b) having someone to bounce ideas and testing to. Maybe that could be you. Be careful when asking for better features; you could be volunteering to be the test guinea pig Seriously though, this area of Stella won't improve unless/until I get more feedback.

I think it's strange too that there's so little interest in cheat codes. I've always loved cheating (in video games, that is). So I wouldn't mind compiling and testing a cht file for Stella, if you can find the time to fix these issues:

- Codes are applied even when turned off

- Pac-Man sometimes crashes when using Bob Colbert's codes (53EEA1 - Unlimited lives, 516EA3 - Power Pills last forever, 5E4EA1 - Able to eat ghosts at any time). Perhaps the codes are faulty; I haven't figured out yet which one (or which combination) is causing the crash. Sometimes it happens, sometimes it doesn't.

- As for the code and its parameters, may I suggest something like:

1. read bank number
2. read address (aaaa) to write to
3. read next value (dd)
4. if value = "&" go to 1 ; a different code coming up
5. if value = "#" then stop
6. write value to address; increase address by 1 and go back to 3

This would make it possible to write multiple values to different addresses in different banks, all in one line of cheat code. It could even be used to make small graphical changes in games.

Btw, thank you for adding the disable sprite collision to your latest version. It works great; I'm having lots of fun with it.

I suggest you add this to the Stella tracker (link is at the top of the page), so it won't be lost. I probably can't get to it right away, but it would be nice get this fixed sometime over the next few months.

[Jim Woolley]

I apologize for the late bump.

I am Rune from GSCentral. You may have heard about me. I am now collecting Stella Cheats and providing them for everyone to use in the Stella format. I have been making videos on our official YouTube channel since yesterday of Atari 2600 Stella codes in action. I would be happy to assist in a project of this magnitude. :-)

P.S. We also support the Cheetah format but it may not be as popular as the Stella cheats.

Edited by Jim Woolley, Tue Jan 3, 2012 2:03 PM.

[stephena]

I welcome some contributions in this area. I understand that there may be some bugs in the cheat handling, and that the editor could be made more intuitive. The problem is, I have a TODO list that I work on, one item at a time. I personally can't work on little bits of different things all at once; I work on one thing, finish it, then move on. So if I start working on the cheatcode stuff, it will mean everything else will have to wait. And I don't necessarily have a problem with that. But I don't want to dedicate my time if there's not much interest, or if nobody is willing to step up and help.

'Help' in this case can of course mean actually sending me codes. But if there's a bug in executing the cheats, or the UI can stand to be improved, I need detailed descriptions. Saying that a "cheat doesn't work sometimes" or "the UI could be better" doesn't help me. Please explain exactly how a cheat doesn't work (what sequence would I have to follow to duplicate the bug?). Or explain exactly how you'd like the UI to work, and how you feel it would help other users.

Sorry to sound confrontational, and this isn't directed at any particular person, but I'm clearly stating I need help to complete this. Stella was recently released as DonationWare, and in this case donating your time and/or knowledge can be just as helpful as a monetary or physical gift.

EDIT: As for my availability, I just released Stella 3.5, with a 3.5.1 bugfix release later this month. I'm already committed to adding Blargg TV effects filtering for 3.6, probably in the February-March timeframe. If I can get sufficient help, I can work on the cheatcode stuff for 3.6, otherwise it will have to wait until 3.7.

[Jim Woolley]

If even a basic Stella extended cheat searcher could be created, myself and many others in the game enhancer community would be all over making new cheatcodes for the Atari 2600/5200/7800, etc. :-)

I have made all of the videos that I can of the codes that have been made thus far. The videos can be found on our Youtube channel. I would happily help create dozens of codes if a cheat searcher could be made for the masses.

[stephena]

Jim Woolley, on Fri Jan 6, 2012 12:40 AM, said:

If even a basic Stella extended cheat searcher could be created, myself and many others in the game enhancer community would be all over making new cheatcodes for the Atari 2600/5200/7800, etc. :-)

I have made all of the videos that I can of the codes that have been made thus far. The videos can be found on our Youtube channel. I would happily help create dozens of codes if a cheat searcher could be made for the masses.

There is a wonderful cheat searcher; the debugger The search and (especially) the compare buttons in the RAM area of the debugger were added for this. The following is a simple procedure I use:

• start a game
  
• go into the debugger, select search, but don't search for any value
  
• doing this will highlight all RAM values
  
• go back to the game, lose a life
  
• go into the debugger, the click on 'Compare' button, searching for -1 (this looks at all highlighted values and finds those that are "one less" than before, hence the -1)
  
• if there are more than one, lose another life and repeat the procedure
  
• eventually, you will narrow down the address containing number of live; once you do, try changing it to some value and see if it makes a difference
  
• once you find the address of lives, create a cheat for it (see the manual for more info)

There's another procedure explained at the end of the Stella debugger documentation. It's more involved, but shows another way to create a cheat.

I'm not entirely sure what a 'cheat searcher' would do. Maybe you mean to automate some of the above? Maybe it could be done for some simple cases, but I don't think there's way to code something that duplicates human intuition. There's just too many ways to create a cheat.

If you have a clearer description of what a cheat searcher would do (perhaps by illustrating how other emulators do it), then please forward more info.

EDIT: I'd also suggest that you include a link to your Youtube channel here.

[Jim Woolley]

Any suggestions on how to convert an address into a code? I have a few incomplete addresses for codes that I was hoping to convert over into stella extended cheats. If I knew how to do that, I could hack more cheats.

Edit: Sure. I've added other videos since, but all of the Atari videos I've made can be found at youtube.com/gscentral

Edited by Jim Woolley, Fri Jan 6, 2012 8:59 PM.

[Trinity]

Is there a way to get the space invaders double fire trick to work with Stella?

[stephena]

Jim Woolley, on Fri Jan 6, 2012 8:58 PM, said:

Any suggestions on how to convert an address into a code? I have a few incomplete addresses for codes that I was hoping to convert over into stella extended cheats. If I knew how to do that, I could hack more cheats.

The cheatcode section of the Stella manual explains this. Perhaps if you provide one example of the addresses you have, I can step you through creating a code from it.

[stephena]

Trinity, on Sat Jan 7, 2012 7:38 AM, said:

Is there a way to get the space invaders double fire trick to work with Stella?

Yes, but it's not particularly intuitive. Start up Stella and go to the ROM launcher. Right-click and select 'Override properties', then 'Hold Reset down' and finally 'OK'. Then start Space Invaders.

All this is really doing is using the 'holdreset' commandline argument. So if you're launching Stella from the console, simply type 'stella -holdreset ROMNAME'.

[Trinity]

stephena, on Sat Jan 7, 2012 8:26 AM, said:

Trinity, on Sat Jan 7, 2012 7:38 AM, said:

Is there a way to get the space invaders double fire trick to work with Stella?

Yes, but it's not particularly intuitive. Start up Stella and go to the ROM launcher. Right-click and select 'Override properties', then 'Hold Reset down' and finally 'OK'. Then start Space Invaders.

All this is really doing is using the 'holdreset' commandline argument. So if you're launching Stella from the console, simply type 'stella -holdreset ROMNAME'.

Thanks, I like it!!!!