AfterZhev
AfterZhev is a small RPG that runs on a single 16 MHz ATmega2560 microcontroller, plus some passive components, and is compatible with the Arduino Mega 2560. Perhaps unwisely, it was written entirely in AVR assembly. The game is intended to be played on a physical microcontroller along with a VGA monitor and a NES controller, but you can also play online here!
Building AfterZhev
A prebuilt HEX file containing the most recent version of AfterZhev should be in the bin/ directory. However, you may want to build the game yourself.
Dependencies
- AVRA, an open source AVR assembler. The Atmel Studio assembler may be compatible, but I have not tested it.
- GNU Make.
- SDL2, for graphics and audio when running AfterZhev on a computer.
- Emscripten, used to run AfterZhev in a web browser.
- avrdude, to program the microcontroller.
- flhex, to work around an Arduino bootloader bug.
MCU build
The microcontroller build is intended to be run on a physical chip, or with the full simulator (make debug). To build it, set TARGET=1 and run make. The resulting HEX file is correct, but uploading it will expose a bug in the Arduino Mega bootloader. Running flhex on the HEX file will fix that. Finally, you can use avrdude to program the microcontroller. If you're using an Arduino Mega 2560, make upload should do the job.
$ TARGET=1 make
...
$ flhex bin/afterzhev.hex -o bin/afterzhev.hex
$ make upload
To test the MCU build on a computer, use make debug. This runs a simulator (sim/simulate_full.c) that emulates a VGA monitor, NES controller, and speaker.
PC build
For testing and convenience, AfterZhev can be run on a computer. The microcontroller is simulated with slimavr and can run much faster than real time. The PC build is largely identical to the MCU build, but for performance and simplicity, it takes a few shortcuts. Specifically, it fakes an NES controller by twiddling memory directly, generates better quality audio, and doesn't generate a VGA signal. To produce a PC build, set TARGET=0 and run make sim to build the AfterZhev and compile and run the simulator (sim/simulate.c).
WASM build
The WebAssembly build is identical to the PC build, but the simulator is compiled with emcc instead of gcc. The resulting simulator can then be run in a web browser. This is significantly slower but still easily runs at the intended 60 frames per second, thanks some shortcuts. To produce a WebAssembly build, set TARGET=0 and run make wasm. You'll have to first run make clean to delete native object files if you ran make sim earlier.
Additional
For information about running AfterZhev on a physical microcontroller and constructing the supporting electronics, visit the project website. You may also be interested in Peten Paja's Toorum's Quest II or the Uzebox project.