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Gameboy development examples and tools

GBSlides

Description

GBSlides is a simple GameBoy Powerpoint-like slides viewer I built to learn how programming the GameBoy in Z80 Assembler was back in the early 90s. As building a game is quite time consuming and I was going to give a talk at an event, I decided to give the talk using a GB emulator and tool built by me.

The result is gbslides.asm file. It uses gameboy Maps/Backgrounds to load slides on them and display one at a time. As editing inside a Tile Editor like GBTB is tiring for simple text, I also made a script that transforms from plain text files to .INC files that have Assembler code defining the backgrounds (GB had no "files", everything was inside the ROM as binary data).

Small demo:
Sample presentation inside VisualBoyAdvance

The "real" presentation is available at: slides.kartones.net

And as was hard to gather all tools and documentation, I've setup a zip containing a nice development toolset at: https://kartones.net/downloads/gbdevpack.zip

Usage

  • First you must compile the source code to generate a binary GB ROM file. I have used the RGBDS compiler:
rgbasm -o gbslides.o gbslides.asm
rgblink -o gbslides.gb gbslides.o
rgbfix -v -p 0 gbslides.gb
  • Then, simply load the ROM into a Gameboy emulator (or transfer to a real cartidge). A button goes to the previous slide, B button advances to next one.

  • Format for slides is quite easy, I recommend checking the asciitomapasm.rb Ruby script and tileset.gbr to see which characters and symbols are available to convert to Tiles.

  • Each slide gets transformed into Map/BG data (backgrounds are not animated, composed by tiles and very easy to handle).

  • To add or remove slides, or edit their content, just edit the txt files inside \slides folder, then run ruby asciitomapasm.rb from this project's root, then edit