12 replies to this topic

[prostx23]

Hi Folks,

After reading this very facinating thread...

http://www.atariage....st-ai-question/

I was wondering if anyone could tell me how closely the 7800 version of Ms PacMan's AI resembles the arcade version. Despite the fact that GCC programmed both, I wonder if it may have been difficult to emulate the Arcade's AI. Ms. PacMan's programming was an overlay of the original PacMan and it seems some of the overrides GCC put in place for the Ghost logic didn't take properly, and there may have been some unintended quirks. I've played the arcade version very little, so I have no way of knowing by "feel" how close the two are.

Thanks,
Mike

[prostx23]

...if noone here knows, can someone point me in the direction of someone who might. Based on the thread I linked to, I wonder if the GCC guys programmed the ghost logic the wat they originally intended to for the arcade version, but couldn't quite get there because some of the old PacMan code overrode their new code.

[PacManPlus]

Hey Mike:

There is a *perfect* complete explanation of how the arcade code works here: http://home.comcast....mandossier.html

Having said that, the original 7800 Ms. Pac-Man is pretty close approximation of what the arcade does.

I tried to make the AI even closer in Pac-Man Collection, replicating the 'error' that happens in the arcade with Pinky and Inky's "up" algorithm. I also tried to recreate the directional 'choices' like the arcade when more than one direction is the same distance to the target (that wasn't there before).

I don't think you could ever get close enough to mimick the arcade AI perfectly, due to the great difference in the screen resolution (I would love to be proved wrong on that, but I don't think it's possible). The arcade Pac-Man/Ms. Pac-Man is 224 (H) X 288 (V), whereas the 7800's resolution (for Ms. Pac-Man) is 112 (H) X 198 (V) - or 204 (V) for Pac-Man Collection. Although things like collision detection, direction processing, etc. do use 'tiles' instead of pixels for their algorithm, the movement of the sprites themselves do not. I believe I've modified the code for Pac-Man Collection to come as close as possible to the arcade AI, especially after reading Jamey's article. You can even rarely move through a monster unharmed in Pac-Man collection - just like the arcade.

Hope this helps.
Bob

[prostx23]

PacManPlus, on Sat Jan 1, 2011 1:26 PM, said:

Hey Mike:

There is a *perfect* complete explanation of how the arcade code works here: http://home.comcast....mandossier.html

Having said that, the original 7800 Ms. Pac-Man is pretty close approximation of what the arcade does.

I tried to make the AI even closer in Pac-Man Collection, replicating the 'error' that happens in the arcade with Pinky and Inky's "up" algorithm. I also tried to recreate the directional 'choices' like the arcade when more than one direction is the same distance to the target (that wasn't there before).

I don't think you could ever get close enough to mimick the arcade AI perfectly, due to the great difference in the screen resolution (I would love to be proved wrong on that, but I don't think it's possible). The arcade Pac-Man/Ms. Pac-Man is 224 (H) X 288 (V), whereas the 7800's resolution (for Ms. Pac-Man) is 112 (H) X 198 (V) - or 204 (V) for Pac-Man Collection. Although things like collision detection, direction processing, etc. do use 'tiles' instead of pixels for their algorithm, the movement of the sprites themselves do not. I believe I've modified the code for Pac-Man Collection to come as close as possible to the arcade AI, especially after reading Jamey's article. You can even rarely move through a monster unharmed in Pac-Man collection - just like the arcade.

Hope this helps.
Bob

Hi Bob,

Thanks for the reply. I'm familiar with the site you linked, I've been reading it in bits and pieces over the last few days. This all started because I recently got the most recent version of the PacMan plug and play. Up till now I've always assumed that Ms. PacMan's AI was an exact copy because GCC programmed both, I just figured the graphics were what had to take the neccessary hit. After poking around trying to find some tips and patterns that I could use for my plug and play, I ran into the Pac Man Dossier. I guess my next question is how closely the plug and play follows the arcade?

BTW: I love PacMan Collection I play it in emulation, If I ever find it in cartridge form at the same time that I actually have the money to buy it. I'm going to snap it up.

Mike

Edited by prostx23, Sat Jan 1, 2011 1:57 PM.

[HammR25]

prostx23, on Sat Jan 1, 2011 1:55 PM, said:

BTW: I love PacMan Collection I play it in emulation, If I ever find it in cartridge form at the same time that I actually have the money to buy it. I'm going to snap it up.

Mike

It'll be waiting for you next time you actually have the money to buy it:

http://atariage.com/...ct_detail&p=849

[prostx23]

HammR25, on Sat Jan 1, 2011 2:36 PM, said:

prostx23, on Sat Jan 1, 2011 1:55 PM, said:

BTW: I love PacMan Collection I play it in emulation, If I ever find it in cartridge form at the same time that I actually have the money to buy it. I'm going to snap it up.

Mike

It'll be waiting for you next time you actually have the money to buy it:

http://atariage.com/...ct_detail&p=849

LOL... this is going to seem ultra stupid, but I never noticed the store link at the top of the page. I was used to seeing it on the left and assumed it was shut down when it wasn't there anymore... time to get my eyes examined. As soon as I get my post Christmas finances in order (Feb) I'll be buying that Cart!

[Metal Ghost]

Is anyone else having trouble with the store? The only page I can get to is for the 2600 magnets. All links seem to bring me there

[Chuplayer]

Metal Ghost, on Mon Jan 3, 2011 2:52 PM, said:

Is anyone else having trouble with the store? The only page I can get to is for the 2600 magnets. All links seem to bring me there

You're not the only one.

[Metal Ghost]

Chuplayer, on Mon Jan 3, 2011 4:27 PM, said:

Metal Ghost, on Mon Jan 3, 2011 2:52 PM, said:

Is anyone else having trouble with the store? The only page I can get to is for the 2600 magnets. All links seem to bring me there

You're not the only one.

Thanks for the response Chuplayer. I hate to say misery loves company, but..... J/K

I'm hoping this gets fixed soon. Does anyone know if it's even known about by the 'powers that be'?

Also, sorry for hijacking this thead for this (really!). If I need to create a thread about it (in marketplace??) I can do that. The only reason why I started discussing it here is because I tried to get to the store to purchase the Pac Man Collection after reading Pac Man Plus' comment and this thread in general, but couldn't get to the page.

Edited by Metal Ghost, Wed Jan 5, 2011 2:58 PM.

[Chuplayer]

Metal Ghost, on Wed Jan 5, 2011 2:56 PM, said:

Chuplayer, on Mon Jan 3, 2011 4:27 PM, said:

Metal Ghost, on Mon Jan 3, 2011 2:52 PM, said:

Is anyone else having trouble with the store? The only page I can get to is for the 2600 magnets. All links seem to bring me there

You're not the only one.

Thanks for the response Chuplayer. I hate to say misery loves company, but..... J/K

I'm hoping this gets fixed soon. Does anyone know if it's even known about by the 'powers that be'?

Also, sorry for hijacking this thead for this (really!). If I need to create a thread about it (in marketplace??) I can do that. The only reason why I started discussing it here is because I tried to get to the store to purchase the Pac Man Collection after reading Pac Man Plus' comment and this thread in general, but couldn't get to the page.

I already created a thread about it in that feedback or whatever subforum. It's near the bottom of the forum list. It's temporarily offline because of USPS rate changes and other technical issues.

[jpittman]

PacManPlus, on Sat Jan 1, 2011 1:26 PM, said:

I believe I've modified the code for Pac-Man Collection to come as close as possible to the arcade AI, especially after reading Jamey's article. You can even rarely move through a monster unharmed in Pac-Man collection - just like the arcade.

As the author of the Pac-Man Dossier and a fan of all things Pac, I would love to see the Pac-Man Collection. I do not own a 7800 however. Is there a version available that would work on an emulator (like MESS)?

J

[tep392]

jpittman, on Thu Apr 28, 2011 9:45 PM, said:

PacManPlus, on Sat Jan 1, 2011 1:26 PM, said:

I believe I've modified the code for Pac-Man Collection to come as close as possible to the arcade AI, especially after reading Jamey's article. You can even rarely move through a monster unharmed in Pac-Man collection - just like the arcade.

As the author of the Pac-Man Dossier and a fan of all things Pac, I would love to see the Pac-Man Collection. I do not own a 7800 however. Is there a version available that would work on an emulator (like MESS)?

J

Sure is. Try this one.

Edited by tep392, Thu Apr 28, 2011 10:36 PM.

[jpittman]

tep392, on Thu Apr 28, 2011 10:33 PM, said:

Sure is. Try this one.

Thanks much!

J