jwierer

Can you post the source for the first level? [Edit] Never mind. I figured out the maze format.

Editing Jr. Pac-man is a little different. First of all, there are no shared portions (thank you Bob), and it is nearly contiguous memory locations. The best way to describe it is reading in a row of 17 bytes in reverse order and drawing it on screen. There are three "sections" if you will that you read in so it does make it a little tricky to decode to an editor since you want to see it all in correct order. Anyway it was really hot yesterday so I played with this until the fireworks came and then figured out what I was doing wrong this morning and voila! Once I had the editor in place it was pretty trival to make changes so now I have a proper Title screen for my Jr. Ms. Pac Hack. For anybody keeping track here is the binary with a modified title screen JRMSPAC_78.5.bin -Jeff

First of all Happy Independence day to everybody in the United States of America! I've known where the title screen is stored for a long time, but never bothered editing it, because using my sprite editor (see earlier post) it's kind of hard to really envision what a 64x30 title graphic looks like. With the non-Jr Pac-man games, you read a nibble, draw 2 pixels, shift down a row, read a nibble, draw 2 pixels. I expected when I drew it on screen I would see a single contiguous stream of data that says Ms. Pac-man. Wishful thinking... It starts off looking good, but then turns to garbage. Wisely, when GCC built the title graphic it was designed for optimizing ROM space so empty tiles aren't stored. Instead sections of graphics are placed strategically at different locations to create the graphic. Of course when you place them in the correct locations it starts to take shape. What you'll notice about this image is missing sections, highlighted in pink. These are actually what I would call "shared" in that GCC reused sections of the title screen in portions where the tiles are effectively the same set of pixels. You can see the color shaded sections of title screen that are reused. Once you know this you can decode the entire title graphic. So yes, it is technically possible to edit the title screen just by modifying the binary, but you'll have to take special care around working on the shared sections, which makes it prohibitively difficult. The "Ms." portion is available in all Ms. Pacman and Pacman variants, except Pacman Collection, for editing which makes it the most obvious place to hack. Happy 4th, Jeff

I would say the bulk of first time user errors is setting up the environment variables, which vbB does for you, or for users that place the compiler in a long file path with spaces. For simplisity sake I would suggest putting bB and vbB in c:\bb or something simple like that and try again. -Jeff

Good idea. I just implemented command line switches. Here's the usage: BMPTo2600 image.bmp code.asm -p/s -r/n For flag three use -p if it is a playfield and -s if it is a sprite For flag four (Only really needed for playfields) use -r for reflected and -n for normal You can simply use the first three flags if you want, but note that if you use a playfield it will be set to normal (Non-reflected): BMPTo2600 image.bmp code.asm -p/s Same download as before. Cool I'll have to try it out again. This might be something I could easily integrate with Visual bB now! Thanks, Jeff

A little background on tunnel support in the various Pac-man roms. Pacman supports horizontal tunnels and Jr. Pacman supports vertical tunnels (you'll see that in the Teddy Bear maze). I did some digging around for the various Pacman variants that Bob released over the years following Pacman. Luckily they all have the same rom locations for mazes and graphics so they work in my editor! While looking at Hangly Man's 2nd level I noticed something interesting... Yes that's a vertical tunnel. Apparently the logic for vertical tunnels was included in this hack. There is also a level in Pac-man collection with a vertical tunnel so the code made it's way there as well. A word of caution, depending on the location of the tunnels it can have unpredictable results such as floating ghosts. I tried this on a WIP hack of Caterpillar, which was an arcade hack of Pacman. I present Hangly Caterpillar

One thing that had been bothering me is that after changing the graphics for the fruits the text was wrong. Searching through the rom using HOM3 didn't yield anything useful. Finally I gave up and asked Bob how text is stored in the Pac-man games and as usual, he provided the necessary info for me to solve my problem - thanks Bob! (I probably should have just asked up front and saved myself a few hours) As you probably already guessed, the text strings aren't stored using standard ASCII codes, for the post part it is the ASCII code + an offset value. If you have just that amount of information you can start hacking the text using HOM3. So in a couple hours I used slightly modified code from the HOM3 text editor and added this new tab to the application. It's a pretty basic editor that allows you to search for text strings and then edit them. Nothing fancy, but it does the job. Here is a screen shot of the the fixed fruit names in my Jr. Ms. Pac-man hack and here is the updated binary if you want to give it a try JRMSPAC_78.4.bin

That's pretty bizarre because all that does is store the contents of the sprite as a string into the clipboard. I'll send you something that traps that error, but it's as if you don't have access to your own system clipboard which probably indicates a permissions problem on your PC. -Jeff

Are there command line switches or is the only way to use it is via the text menus? -Jeff

I love DK3. That game is missing in the Atari and Colecovision library. I would buy that one in an instant. -Jeff

I think I fixed that in a private build I sent you. If that doesn't work, please PM me the source so I can step through it and see what is happening. -Jeff

I think I fixed that in a private build I sent you.

Finally got around to adding the functionality to edit the graphics. For now it's just a fixed sized "tile" editor, but it does work so now you can change most aspects of the Pac-man series of games for the 7800. The only other thing I thought would be novel would be changing the number of start lives, but I am not sure I want to go through the effort of identifying where that is done. You can assign "viewing" colors for the 2 bits (4 colors) for the tile editor. You can assign those colors to either the left or right mouse bottons. Double clicking sets a pixel (2 bits) on the tile editor. Copy and paste works so you can use the clipboard on another tile. I may attempt something more adaptive, but I will settle for funcitional for now. So for now this is what the graphics editor looks like. As a small change for my previous hack, I changed the dots to hearts. I believe there was a Ms. Pac-Man arcade hack that did this. and if you want to play it you can download it JRMSPAC_78.3.bin

Ok I figured it out. Using Regedit change 0F to 0E. Problem should go away. -Jeff

Ok those seem fine. Have you checked the contents of your sprite? Does it look normal? Can you open other sprites or create new ones? BTW if you don't mind resetting all your vbB settings you can close the application, delete that registry key, and re-open the vbB. It will recreate the defaults. Just in case it's a setting issue... -Jeff

If you peek in the registry [HKEY_LOCAL_MACHINE\SOFTWARE\VisualbB] what are the settings for these? "_DEFAULTBACKCOLOR" "_DEFAULTPLAYERCOLOR" "_DEFAULTPLAYFIELDCOLOR" -Jeff

I don’t know much about 7800 graphics so I started reverse engineering them in Hack-o-Matic III and Tile 'M So far this is what I’ve discovered. Jr. Pac-man has a couple banks of sprites starting at 0x0 and 0x6000 both of length 0xF00. Each sprite is read left to right and rows are separated by 0x100 (256) bytes. Each Pixel is 2 bits so the first 2 bytes represents the first row. The 2 bit value determines which color in the palette is used. (00 = color0, 01 = color 1, 10 = color 2, 11 = color 3). Here is how you would read the first sprite in the second bank of graphics. Row 0 [0x6000 -0x6001] Row 1 [0x6100 -0x6101] Row 2 [0x6200 -0x6201] Row 3 [0x6300 -0x6301] Row 4 [0x6400 -0x6401] Row 5 [0x6500 -0x6501] Row 6 [0x6600 -0x6601] Row 7 [0x6700 -0x6701] Row 8 [0x6800 -0x6801] Row 9 [0x6900 -0x6901] Row 10 [0x6A00 -0x6A01] Row 11 [0x6B00 -0x6B01] Row 12 [0x6C00 -0x6C01] - Always Blank Row 13 [0x6D00 -0x6D01] - Always Blank Row 14 [0x6E00 -0x6E01] - Always Blank Row 15 [0x6F00 -0x6F01] - Always Blank Since this will result in an image that is upside down it should be flipped for easy viewing. All the other games in the Pac-man series store sprite data differently. Data is also read left to right, with the exception that rows are sequential so you can read in a sequential set of 32 bytes. Colors work the same. The only problem with this is that graphics wrap so sometimes you need to edit 2 sprites to really edit the image. Row 0 [0x6000 -0x6001] Row 1 [0x6002 -0x6003] Row 2 [0x6004 -0x6005] Row 3 [0x6006 -0x6007] Row 4 [0x6008 -0x6009] Row 5 [0x600A -0x600B] Row 6 [0x600C -0x600D] Row 7 [0x600E -0x600F] Row 8 [0x6010 -0x6011] Row 9 [0x6012 -0x6013] Row 10 [0x6014 -0x6015] Row 11 [0x6016 -0x6017] Row 12 [0x6018 -0x6019] - Always Blank Row 13 [0x601A -0x601B] - Always Blank Row 14 [0x601C-0x601D] - Always Blank Row 15 [0x601E -0x601F] - Always Blank

Don't forget Pac & Pal. Game play is different, but Super Pac-man is probably something that can be built upon. -Jeff

Ran into an interesting problem this morning. Ever noticed that when you start a level it says "Ready" under the ghost pen? By writing and erasing that text it also erases any dots you may have placed in that region. The problem with that is that you can never eat those dots so it never counts them as being eaten and therefore the level can never be cleared For some reason this also affects the region above the ghost pen. This creates an non-editable zone (see picture). Also apparently there are some Plus Colors and Graphics in Jr. Pac-man. After starting the game, I pausing a second and then figured out how to get it to play. ...and here is an updated Jr.Pac-man hack that changes the Plus mode colors and fruits. JRMSPAC_78.2.bin

That's awesome. I thought those were leftovers from the other hacks, but I should have known better since you did so much to control rom space and ram usage. I guess I'll have a another set of colors to find... -Jeff

It's actually a hack of Jr. Pac-man, not Ms. Pac-man. The graphics are crappy because I had to re-create them by hand -Jeff

Thanks. It's actually quite easy to change the mazes now The two things I didn't do was update the title, know where it is just not that graphically talented, and changing the names of the "fruits" - I couldn't figure out how those were stored. Game play appears to be pretty good though. -Jeff

I tried implementing that once, but there is something about how it counts ticks when you scroll in a tab control that would cause it to keep scrolling up. I could never figure out if it was something I was doing or a limitation of the control. Eventually I just gave up on keeping preview always on the screen. Yeah I noticed that as well. Definitely not something I am forcing it to do. Once again I think it's a limitation of scrolling in a tab control. -Jeff

Actually, Jr. Pac-man does support vertical, not horizontal tunnels. This was added to support the Teddy Bear level. Give this a try. JRPAC_78_Tunnels.bin I think it makes game play easier. Coincidentally I *just* posted a more expansive hack in my blog. -Jeff

I was playing with my Pac-man Construction Set looking for bugs and got a little bit carried away. After spending another hour with Tile-Molester I came up with this Maze and graphic hack for Jr. Pac-man. The central parts of the mazes and colors should be familiar from Ms. Pac-man, Pac-man and Puck-man. The outer mazes are still parts of Jr-Pacman. The graphics are miniature versions of Ms. Pac-man. Here is a screen shot Here is the binary. JRMSPAC_78.bin -Jeff