The only thing you can do without a flash cart, if you have the right cable, is send over Multiboot files: https://web.archive.org/web/20090528045656/http://wiki.pocketheaven.com:80/Multiboot

A modern solution would be to use an Arduino or UART.The only thing you can do without a flash cart, if you have the right cable, is send over Multiboot files: https://web.archive.org/web/20090528045656/http://wiki.pocketheaven.com:80/Multiboot