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
It's been a couple of months since I've posted to my blog. Part of the reason is I've been traveling a lot for work, but the bigger reason is the project I've been working on hasn't been public. I like to be trustworthy so I haven't said anything, but appears the cat's out of the bag on Pacman Plus's newest project for the Atari 7800 so I'm assuming I am free to discuss my contribution For those that haven't heard about Countermeasure 2 Failsafe for the Atari 7800 you can read about it here.
I wasn't quite happy with how I was handling colors in the last build using drop down menus. I also didn't like being limited to a subset of colors. I'm much happier with the color palette and being able to visually see the changes as it looks a lot closer to actual game play.
What's new
You can edit energy dots, dot color, and outer maze color in 7800 Pac-man!
I've changed the font for dots and energy dots to look more like the actual game.
Colors are now implemented for th
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
I was playing with Pac Pollux and got to thinking about how the ghosts were all the same colors. Sure enough this was a hack of Bob's original Pacman hack so a quick comparison of the two in Hack-o-matic 3 exposed all the locations for the ghost colors. After that I started looking for other colors by searching for LDA, <immediate> where immediate is the color I want to find. In HOM 3 this is just a hex search for A9, and the two bit hex code. A couple hours later I had most of the color l
I am done working on a Jr. Pac-man Construction Set and have moved onto a Pac-man Construction Set. So far this is working with Jr. Pac-man, Pac-man Collection, Ms. Pac-man, and Bob’s recent Ms. Pac-man Arcade hack.
On top of supporting additional games and fixing some bugs, the controls are a bit different. You can still select and enter dots, mazes, or energy dots, but now there is a Maze and Dot mode where you can draw freely with the let mouse button and erase with the right mouse butt
After playing upside down Ms. Pacman (see this blog post) i was a little disappointed with where the fruits would appear because they were still set to the original tunnel locations. If that locations happened to be a maze it would warp though it - awkward, but ok. If it had some empty space followed by a maze part the fruit would appear, bounce into the wall and then disappear off into space and you'd never get to eat - not the desired result. Based on some additional technical knowledge I
Ever since I saw Pacman Plus’s original 5200 hack of Pac-man I wanted to create a graphic editor for manipulating Pac-man mazes. I’ve looked at the mazes using HOM3 and other text editors, but the exact format always confused me. Creating a graphical tool is pretty easy, but decoding the maze is another thing! Unlike Beef Drop (aka Burger Time), the mazes are not as straight forward.
Last week Bob shared with me some partial source to Jr. Pac-man. It was just enough for me to finally fig
Now that the Memorial Day holiday is over I took a fresh look at this again. To understand this blog post you need some basic grasp of how mazes, dots, and energy dots are stored.
Mazes
To begin, the 8 mazes are stored as a series of 8 bit codes. Decoded into binary, from lowest to highest bit they are read horizontally. Since the maze is symmetric only half of the maze is stored in the binary. In the editor you will see both sides for ease of development, but placing dots is mirrored
I can't believe it's been over a year since I last touched visualbB. I haven't abandoned the project, was just waiting for batari to release the final DPC+ kernel before making any futher changes. Since Oct 2011 I've only made a couple of tweaks.
1. Support for the titlescreen kernel 1.1
There was a bug reported here when using the wizard with the 1.1 kernel and the DPC+ kernel. In the original titlescreen 1.0 you needed to declare a constant scorepointers = player1x. The code generator
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 a
I was wondering what the game play of Ms. Pac-man would be if the mazes were flipped. So I started recreating the mazes, but that seemed ridiculous tedious so I added a new feature to my Pac-man editor that would allow you to flip items vertically and horizontally. With that I was able to flip each of the mazes, all the graphics and the title screen.
Came across a couple issues when creating this.
Ghost Pen: The Ghost pen isn't really located in the center of the maze and it can't be mo
I've updated visualbB to support the latest WIP version ofthe bB 1.1b compiler. Actually I did this a month ago, but have been a bit busy to take the time to post it. You can read more about bB1.1 from batari'sblog.
Here are some of the changes in visualbB Build 562:
Updated the Titlescreen editor so that you can insert kernels. This will make it easier to modify where before you had to delete and start over if you wanted to change the order.
Fixed a problem with long names and spaces
About once a year I get some external motivation to code. In 2007 I started looking at some of the bit hacking tools bit-hacker, hack-o-matic & HOM ][. They were better than using a hex editor for hacking up 2600 graphics, but lacked some of the flexibility I was used too in other applications. For me bit hacking needed to be a lot more like Microsoft Excel. I actually started by creating an add-on for Excel, but eventually I figured not everybody would have Excel and I wanted to really
This is the last in a series of blog posts on creating different title screens using the title screeen kernel in bB. As with the previous tutorials, you'll need to be using a test version of visualbB. As with the previous two examples you can use the 48x1 mini kernel to create the effect of a multi-colored titlescreen. This is actually achieved through the flickering of colors. In this case, using a red and a light blue when blended appears white(ish). You can play with the colors in step 2
In Jan 2008 I saw this thread about 2600 IDE not supporting .bas files > 64K. That got me thinking about developing an integrated development environment for batariBasic. So I guess Atar2600land should get credit for inspiring VisualbB because if I hadn’t read that post I would have never thought about it. Anyway I figured that it was a limitation of the COM control being used. I vaguely remember that being a limitation in Visual Studio 6. Since I was getting into writing some games using
The other day I spent a little time working on enforcing some rules for the games so that you don’t accidentally create a maze that won’t run.
Ms Pac-man – has 4 levels all 31 cells tall by 29 wide. You can have horizontal tunnels, but not vertical.
Pac-man – Originally based on the Ms. Pac-man code it has 2 levels (get to the second one by using the player select switch) 31 cells tall by 29 wide. You can have horizontal tunnels, but not vertical.
Ms Pac-man (Bob’s Arcade Hack)
I spent a little time on an airplane over the weekend. That gave me some time to look into colors for the maze and dots. A maze is a combination of two colors an outer and inner bar color. Dots are a single color. So for example, in Ms. Pac-man collection there are 4 mazes so there are 12 different locations you can change the colors. On top of that Pac-Man Collection has 21 mazes and can run in “plus” mode which means you have 3*21*2 = 126 different colors you can set using the following 22
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 apparentl
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 colo
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
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 verti
In the fall of 2009 I took some time off from programming and hence my blog as I was traveling heavily for work. When I got back I started to work on VisualbB again by adding some new music and sound editing. I wanted to post my Failsafe editor for some time, but had to wait until the Bob was done tweaking it as the editor would break when various changes were made. Now that Failsafe is available for purchase, I figured it was safe to publish the editor.
Since I created this primarily as
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
If you're like me I like to have a physical cartridge made for hacks and homebrews that never get put onto a cart. For the 7800 enthusiasts that can be a bit challenging as custom 7800 boards are not as easily accessible compared to the 2600 and 5200 Pixels Past boards available in the Atari Age Store (when open). Fear not, for most games 32K or less it's pretty easy to hack up an existing 7800 cartridges to take an EPROM. External memory and larger roms are bit tricker, but just require you
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