Intending to make a portable shmup -- help

[Zweihander]

I know it's possible to transfer a program to a blank cartridge (of say, a GBA cart, for example), so does anyone have sources for cartridge-writing hardware/software? GBA, GB, Game Gear, Atari Lynx... ANY cartridge source would be appreciated. Thanks in advance to anyone who can help me on this... ^^;

[mrMagenta]

for GBA get a flashable backup cart, like XG-cart. i bought mine from lik-sang but i think they removed it from their store because of legal issues. There are still others who sell hem.

for SDK stuff you can check out
http://www.devkitpro.org/

I haven´t tried making anything for GBA myself, so I don´t know more than this