Breakpack Posted October 28, 2003 Share Posted October 28, 2003 Hi.I was messing around with Pac-Man for 5200 and came up with this slight hack.Its really not much,but a start:) I can seem to find the ghost's body graphics while hacking,but I can't find their botton part(interesting that the ghosts are made up of 2 sprites put together.Notice when you eat the pellet,the lower part of the ghosts don't seem to 'fit'.Also,I couldnt find the fruit sprites ,or I woulda changed that.I'm still looking though.I lowered the ghost eyes slightly.If anyone can hack the colors (PacManPlus?),that'd be cool,too.Also wanna try to mod the intermission ghosts.I know the 5200 is capable of making a different color for the flag on top of the scared ghosts,but alas,thats beyond my expertise.I used Atari800Win emu to test it.Let me know what you think.Thanks Oh,I can't upload pcx files(which Atari800Win uses),so I converted this pic to jpeg.Kinda crappy pacmanplus5200.zip Quote Link to comment Share on other sites More sharing options...
PacManPlus Posted October 29, 2003 Share Posted October 29, 2003 Crap! I had found the colors to the 5200 maze several months ago but have since thrown away that piece of paper It took a while to find too... Pretty much trial and error. Unfortunately I haven't gotten any further on the 2600 PMP version; the assembly is just too difficult for me to follow (time to start reading the 'programming' forum) In the meantime, time to look at what looks like a cool job you did!... Quote Link to comment Share on other sites More sharing options...
Breakpack Posted October 29, 2003 Author Share Posted October 29, 2003 Thanks PacManPlus I tried looking at the code for 2600 PMP,but it can't make heads or tails of it .Maybe I need to crack down and study,too .I did notice that the 5200 Pac-Man's ghost sprites are make up of 2 halves.The 'legs' of the ghosts are a seperate sprite,but I couldn't find it (it was all jumbled).I used TileLayerPro to hack into it.Hackomatic took way too long to load(and I never got it to..BSOD after trying Ctl/Alt/Del to stop it).Hopefully,I can find the fruit sprites,but since they have 2 colors(most of them)they may be scrambled and not easy to find.... I'm curious as to how the 'intermission'ghost will turn out since it has 2 colors,too(blue and white).Oh well,I'll keep on it (until I get frustrated...arrrghh ).Right now,Im hungry Waka waka :wink: Quote Link to comment Share on other sites More sharing options...
Breakpack Posted October 29, 2003 Author Share Posted October 29, 2003 Oh this might not be much but I also hacked the 'scoring' numbers.You won't get these points on the 1UP score,but I did change the graphic numbers when eating the ghosts on screen.400,800,1600,3200 pacmanplusscore.zip Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted October 29, 2003 Share Posted October 29, 2003 The graphics for the "fruits" are redefined characters in Antic mode 4 (4 color text mode). In Ram, these are copied to the addresses $31D0 to $326F (cherry to key)...and each one uses 2 characters (left and right half...so the fruit can appear dead-center on the screen). For instance, the "fuji" logo is stored as : $3230 : 22 22 22 22 22 a2 82 82 20 20 20 20 20 28 08 08 ...which would produce: 00100010 00100000 00100010 00100000 00100010 00100000 00100010 00100000 00100010 00100000 10100010 00101000 10000010 00001000 10000010 00001000 See the Fuji? The first 8 bytes create the bitmap on the left, and the next 8 bytes create the bitmap on the right. Bit combinations of 01, 10, or 11 signify the colors of the pixels (the game select screen's text must use the same colors, since no provision is used to alter them when a fruit is displayed). I didn't spend a whole lot of time looking through it, but if you search Atari800Win's F8 monitor you should be able to fine where the program grabs the data from to copy to these locations. As in LDA $????,X / STA $31D0,X (or something like that). Quote Link to comment Share on other sites More sharing options...
Breakpack Posted October 29, 2003 Author Share Posted October 29, 2003 Yikes....can't understand too much.But I have managed to dissassemble the rom in dis6502.I can't find Antic mode 4 and the segment starts at $4000 ...... Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted October 29, 2003 Share Posted October 29, 2003 Right, the 5200's Ram falls below $4000...so in there someplace the character data is copied from the Rom to the Ram locations listed above. Dunno why they chose to copy the character data to Ram rather than just point to a character set in Rom memory (?) Anyone know why they would do this? Quote Link to comment Share on other sites More sharing options...
Breakpack Posted October 29, 2003 Author Share Posted October 29, 2003 I noticed using TileLayerPro mentioned above,I saw two sets of pac-man characters/ghosts.I only hacked the first one's graphics.Dont know what the second copy is for @Nukey Shay:If I keep looking at the dissasembled rom thru dis6502,Ill come across the fruit sprites?Ill have to fiddle around with this program a little more... Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted October 29, 2003 Share Posted October 29, 2003 It doesn't just pull the characters out of thin air I ran across some of those 32-byte "Ghost" characters at $7C00-$7CFF (the ones seen during intermissions) Quote Link to comment Share on other sites More sharing options...
Breakpack Posted October 29, 2003 Author Share Posted October 29, 2003 I meant the in game sprites were repeated.Like doubles or something.I scrolled to the first set and changed the ghost sprites,then I scrolled down (again using TileLayerPro)to see another set of in game sprites.Is this normal? Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted October 29, 2003 Share Posted October 29, 2003 The cart is 32k..which means that bankswitching was used, right? I dunno how the 5200's bankswitching works, but I think it swaps out the entire cart area. Since player/missile graphics are handled by Antic like an interrupt, you would need the data in both banks so that the data can be found when Antic calls it. I guess Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted October 29, 2003 Share Posted October 29, 2003 No bankswitching, the 5200 has a linear address space from $4000-$BFFF. Pac-Man is actually just a bad dump, it's not 32K. Quote Link to comment Share on other sites More sharing options...
Breakpack Posted October 29, 2003 Author Share Posted October 29, 2003 It doesn't just pull the characters out of thin air Der...I really showed my brilliance there lol....... Quote Link to comment Share on other sites More sharing options...
PacManPlus Posted October 29, 2003 Share Posted October 29, 2003 I actually started with the 16K version of Pac-Man when I began this a few months ago @NukeyShay: Thanks for the explanation; I follow things a little better now @Breakpack: I'll take a look at this also over the weekend.... Quote Link to comment Share on other sites More sharing options...
Breakpack Posted October 29, 2003 Author Share Posted October 29, 2003 I actually started with the 16K version of Pac-Man when I began this a few months ago @NukeyShay: Thanks for the explanation; I follow things a little better now @Breakpack: I'll take a look at this also over the weekend.... Where did you get the 16K?I just got the 32K Quote Link to comment Share on other sites More sharing options...
Tempest Posted October 29, 2003 Share Posted October 29, 2003 Where did you get the 16K?I just got the 32K Look around on the various rom sites. The game is supposed to be 16K, but was padded with an extra 16K worth of garbage (usually just the rom copied twice) so it would work with the old emulators. It isn't needed anymore, but the old rom dumps remain out there. Tempest Quote Link to comment Share on other sites More sharing options...
DEBRO Posted October 29, 2003 Share Posted October 29, 2003 Where did you get the 16K?I just got the 32K You can use the ROM here and use something like HexEdit to remove the doubled bytes until $8000. This is generally what I do. Once you do that and send it through Dis6502 the code should make more since. Quote Link to comment Share on other sites More sharing options...
Breakpack Posted October 29, 2003 Author Share Posted October 29, 2003 I found it Quote Link to comment Share on other sites More sharing options...
PacManPlus Posted October 29, 2003 Share Posted October 29, 2003 @Breakpack - by the way, the 'doubled' values of the points while the monsters are blue only happens when you eat the fruit; the energizers still give the normal points... (not sure if you know that or not, just trying to help) Quote Link to comment Share on other sites More sharing options...
Breakpack Posted October 30, 2003 Author Share Posted October 30, 2003 Yeah....just wanted to see how it'd look,in case the hack comes to fruition Quote Link to comment Share on other sites More sharing options...
Bryan Posted November 2, 2003 Share Posted November 2, 2003 Could you guys post the addresses of what you find? I'd like to poke around. -Bry Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.