Ghostown & Whelpz 2025

"Perfection is achieved, not when there is nothing left to add, but when there is nothing left to take away." - Antoine de Saint-Exupery.

"Everything should be as simple as possible, but no simpler." - Albert Einstein

Introduction

This tutorial works only on Debian 12 or Ubuntu 24.04 Linux for x86-64 architecture. This is the easiest option, period. If you choose other unsupported distribution, system or architecture, then you are on your own – good luck!

IMPORTANT! This Amiga framework is for people that are familiar with Linux terminal and standard Linux C developer tools (gcc, python, make). Please read carefully the documentation to save yourself time on pointless troubleshooting.

The current build status of the repository is .

Setting up build environment

1. Download demoscene-toolchain deb package and install it with all its dependencies.

2. If you haven't had Git LFS installed previously, run git lfs install to enable Git support for binary files. If you don't do this, you'll get text files in place of graphics, audio and other binary files. This will result in various file converters failing.

3. Clone demoscene repository. If you forgot (2) this is the right moment to fix binary files by issuing git lfs pull command.

4. Each time you open a new terminal, go into the repository main directory and run source activate. This verifies that your build environment is set up correctly. It may require you to install extra packages.

The Amiga emulator

You need an emulator to test Amiga binaries. Don't worry demoscene-toolchain provides fs-uae emulator, and you should have it already installed.

My version of fs-uae has been heavily patched. The patches provide betted debugger integration and via UAE traps enable Amiga programs to:

• efficiently output diagnostic messages on Linux console,
• invoke debugger at given breakpoints,
• turn on/off warp mode to skip long initialization times.

IMPORTANT! You must provide Kickstart ROMs for the emulator to function correctly. fs-uae will automatically find the correct kickstart ROMs for all Amiga models if you have copied the .rom files into its kickstart-dir.

My framework does not work with AROS ROM, which is not fully compatible with AmigaOS. The bootloader will just crash!

Compiling source code

Using terminal change directory to cloned repository and issue make command. If your build process fails, then:

• double verify your build environment is set up correctly,
• issue make clean in the main directory and try again,
• make a fresh clone of repository and try again.

If all of the above fails please ping cahirwpz on Discord. Prepare exact steps to reproduce error. Please respect my time and don't ping me because you don't have time to debug the issue.

Running the effect under emulator

1. Change current working directory to effects/ball/ (or other effect in this directory) or demo/.

2. Issue make run command.

   run target for make prepares all files in data directory, builds executable file, creates ADF floppy image from binary files, adds custom bootloader to ADF and runs the launcher tool.

3. Terminal multiplexer tmux is started. It creates 3 panes:

   • fs-uae - with messages from the emulator and UAE built-in debugger.
   • serial - supports bi-directional communication over emulated serial port (9600 bauds).
   • parallel - support uni-directional communication over emulated parallel port (fast). To switch between panes use CTRL+b n, where n stands for pane number.

4. All messages written to fs-uae pane will be saved to corresponding log file, that is - for effect ball, file ball.log will be created.

5. (optional) You can interrupt emulated program by pressing CTRL+C in fs-uae pane. You'll enter UAE built-in debugger. Type ? for help, or type g to continue execution.

6. To stop emulation either close fs-uae window, or press CTRL+b d in terminal. The latter choice detaches tmux from terminal, which initiates session shutdown.

Debugging the effect under emulator

Sometimes you need to tune your effect or fix some bugs. Depending on the complexity, you can use either console logging or low level UAE built-in debugger. But for your utmost convenience, in addition to those ancient debugging techniques, the toolchain comes with AmigaHunk executable debugger!

The debugger is nothing more than well known GDB: The GNU Project Debugger. It's a very powerful tool (believe me!) but the default interface is not the most user friendly one! Too soothe the experience you should install great GDB overlay gdb-dashboard. In root directory of cloned repository issue a command wget -O gdb-dashboard https://git.io/.gdbinit and you are done! Now, you can quite comfortably debug your effects in a terminal.

Now, just navigate to a directory with given effect and issue make debug command. debug make target behaves the same way as run make target. It prepares all the prerequisites and launches the effect in the emulator. But, in addition, it runs a GDB process, so all you need is to know how to talk with it. After playing with some basic GDB commands like breakpoint, step, next and continue, you should be able to see a terminal view similar to given below. It looks massive! Isn't it?

Setting up Visual Studio Code IDE

Terminal based approach is more productive when you are low-level geek. But what if you're not GDB aficionado? Fortunately there's option for you as well. Though we still encourage you to learn GDB – it will pay off eventually ;-)

In such a case the provided Visual Studio Code integration should help. Oh yes! You can use modern IDE with all its advantages for Amiga development!

First of all, you have to install Visual Studio Code for your favorite platform. Then, using its extension explorer install following extensions:

• C/C++ (required)
• Python
• m68k
• Better C++ Syntax
• GNU Linker Map files
• Git History
• File Utils

The first one is required, but others are recommended for your convenience.

Having the installation done, navigate to root directory of cloned demoscene repository, type code . and Visual Studio Code IDE will open the current directory as a workspace. Go to the .vscode folder and open settings.json in the editor view. Among other settings you can see "effect": "anim" setting which tells the IDE that all operations like clean/build/run/debug have to be performed on anim effect. You can change it to any other effect located in effects folder or use a special variable "effect": "${fileDirnameBasename}" which means that current opened file's folder name will be used to identify the effect for all operations mentioned above.

Now, open the .vscode/keybindings.json and copy its contents. Press Shift+Cmd+P and start typing Open Keyboard Shortcuts (JSON). When this option appears on the list - choose it. It will open user's key bindings configuration file where you have to paste already copied contents.

Since now, you can use following keyboard shortcuts:

• Shift+Cmd+C - Clean output files of single effect
• Shift+Cmd+B - Build single effect
• Shift+Cmd+R - Run the effect without debugging
• Shift+Cmd+D - Start debugging the effect
• Shift+Cmd+A, Shift+Cmd+C - Clean all output files
• Shift+Cmd+A, Shift+Cmd+B - Build all effects

These shortcuts are macOS specific. For other operating systems please refer to Visual Studio Code documentation for information which key to use instead of Cmd.

All these actions are handled by Tasks defined in .vscode/tasks.json. You can also press Shift+Cmd+T or use Terminal->Run Task... menu item to call any of the above actions.

Let's check how it works. Open the effects/anim/anim.c source code file and set the breakpoint somewhere in the Render function. Press Shift+Cmd+D and... enjoy how modern Visual Studio Code IDE is supporting Amiga demoscene development!

If you managed to get through the steps successfully, congratulations! You have probably the most sophisticated cross development environment for Amiga 500 at your disposal!