Copyright © 2015 by Víctor Parada

Toy'Swap board

This is my 1st game for the Atari XL/XE computers written 100% in assembly language. It is based on Food Swap minigame from Pou virtual pet.

This game was not programmed neither in a real Atari nor an emulated one, I decided to use a cross-compiler, i.e. a compiler that runs in a Windows PC and generates Atari 8-bit executables. This way, it could be faster to do some simple tests and a proof of concept for my idea. At that time, it seemed that Tebe's MADS Assembler was stable enough and had interesting features to speed up the coding process. It took me about 99 programming sessions, some of them of few minutes, but usually between 2 and 5 hours, most of the time playing testing ;-)

The game uses ANTIC 4 mode for the graphics and ANTIC 6 for the counters under the board. Fonts where created using Matosimi's FontMaker. It also uses Player/Missiles (P/M) graphics to add more elements to the game, with Display List Interrupts (DLI) to position them on the board and to change their colours.

It became an interesting variation of the game as I was adding more and more elements to it and changing the rules. At some point of the development, I decided to finish it like a commercial product and register into the annual ABBUC Software Contest. That required to include a title screen with music and also background music during the play of the game.

Toy'Swap title screen

As I didn't want to start from scratch, the first step to include music and sound effects in the game was to choose one of the music trackers available to the 8-bits Ataris, and Raster Music Tracker (RMT) was the recommended one. Its SFX demo played OK as background music, and didn't crash my DLIs and VBI. From that demo I took and tweak some of the sound effects that you can hear during some game actions. The final main theme that was included as both title and background music was the result of a quick try to learn RMT's editor usage and an intend to reproduce Food Swap background music, but I finally gave up and wrote my own variation of it. Be aware and cover your ears!

The following is a gameplay video of Toy'Swap (YouTube):

ABBUC 2015 took place on October 24, and Toy'Swap got the 3rd prize in the software contest.

You can download ABBUC 2015 version here:

You can play it on a real NTSC or PAL Atari with your favourite game control: joystick, trackball, lightgun, keyboard or ST mouse.

Please note that on NTSC machines, music is 1/5 faster than on PAL machines, but the game timers are the same for both systems.

You can read the full story in spanish at Retronia's forum.

Toy'Swap - Copyright © 2015 by Víctor Parada - 2015/10/25 - Last update: 2016/04/22