I used to hack around with GBA programming too, but I started much earlier on an Apple ][. My first serious attempts at assembler programming were on the TI-85

I used to hack around with GBA programming too, but I started much earlier on an Apple ][. My first serious attempts at assembler programming were on the TI-85 graphing calculator which had a Z80 processor (same as the original gameboy). Later, I bought a programmable GBA cartridge and a tool that could write to it. There were a Z80 emulators on the GBA to play the original gameboy games, and there were packagers available to make your Z80 programs, so I ported over my "columns" clone I made for zshell on the TI-85.