S: Select Game
Game 1: You vs. the Mad Bomber
Game 2: You and a friend
take turns vs. the Mad Bomber
R: Reset to start a new game
Paddle 0: Player 1 controller
Paddle 1: Player 2 controller
Paddle button starts bombs falling
(Mockingboard required for sound)
Running on actual hardware with good paddles with a Mockingboard sound card is highly recommended. It's the only real way to achieve Kaboom! game play "flow" as experienced on an Atari 2600.
If an Apple II emulator is used, it must emulate the floating bus ("vapor lock") of real hardware. AppleWin and Virtual II emulate it by default. MicroM8 requires enabling Video -> Cycle Accurate Render, else it will hang after launch.
This implementation of Kaboom! uses algorithms taken directly from the disassembled Atari 2600 ROM code (see vcs/kaboom.a), with the goal of matching original game play as closely as possible. Graphics were designed based on the Atari graphic bitmaps as well.
The code was written with high performance in mind in order to run at a solid 60fps. To keep the framerate consistent, optimizations were omitted that only helped in some cases. The code runs at worst-case speed but great effort was made to make the worst-case as fast as possible.
Sound is only provided when Mockingboard hardware/emulation is present. An attempt was made to implement software sound but too few cycles were left per frame to create accurate sound effects. Dropping to 30fps may have made software sound possible but would have degraded game play and compromised the primary goal of duplicating the original game.
The code was developed using the Visual Studio Code editor. Syntax highlighting and editing assistance was provided by RPW 65.
All graphics were created and edited using RPW A2. This extension adds a file system provider for mounting .dsk images and a HIRES graphics editor.
The code was assembled using ca65, mainly because I wanted to familiarize myself with it and compare it to Merlin, dasm, etc. (I'm not really a fan, to be honest -- no HEX directive, required config files, and seeming problems with code that uses alignment directives.)
Finally, the game was debugged using the RPW debugger. This is a web-based Apple II emulator and debugger written in TypeScript that has not been release as of this writing. It will eventually be converted to a VSCode extension and released on the marketplace.
Custom paddles can be created in order to enjoy Kaboom! in the way it was meant to be played, but note that standard Apple paddles will work just fine too.
Building these Apple-compatible paddles is mostly an exercise left to the reader. Below are links and descriptions to the 3D models I designed and the parts needed to build them.
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3D printed parts
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150KΩ potentiometer
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Four conductor cable, 26 AWG each, 4mm outer radius
Search amazon.com for "26AWG UL2464 Power Cable Stranded Electrical Wire Flexible LED Red & Black & Yellow & White 4 Conductors 25ft"
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Cherry MX keyboard switch
MX Black or preference
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Compression spring (optional)
10mm outer dimension, 0.5mm wire, 10mm length
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Cord strain reliever
4mm inner radius
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DB-9 male connector
Search amazon.com for "DB9 Solderless Connector 4Male, DB9 Breakout Connector RS232 D-SUB Serial to 9pin Port Terminal with Case"
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580Ω resistor (up to 1KΩ okay)
Assuming Yellow and Black wires connect to potentiometers and White and Red connect to buttons, connect the wires to the DB9 pins as follows:
Use this wiring information at your own risk!
Wire -> DB9 Pin
---- ---
Y0 -> 5
B0 -> 2
R0 -> 2
W0 -> 7
Y1 -> 8
B1 -> 2
R1 -> 2
W1 -> 1
580Ω resistor from Pin 1 -> 3
580Ω resistor from Pin 7 -> 3