There are many different ways.
Original method:
Get a copy of Phantasy Star online and a broadband adaptor and stream the games from your PC to the GC. Games play slow most don't work. Very long startup time. To backup, you need to send the ripper program through the BBA.
Modified original Method:
Get a copy of Phantasy Star online and a broadband adaptor and send across a program that tells it to stop the miniDVD in the drive and then you swap with a backup (make sure the lid switch is down while you do this) and it plays. This is the method I use, and it takes forever to start, (around 3 minutes per game), requires a swap, and requires a connected PC. Otherwise games play perfect. To backup, you need to send the ripper program through the BBA.
Action Replay Method:
You program in around 80 lines of cheat codes that tell the AR to boot a program off the memory card. Then you put the program that boots backups from the modified original method onto the memory card and lauch it. It has faster load times than MOM, but requires a 40+$ AR disk. It also requires a lot of work to set up, and you need PSO and a BBA at least once. To backup, you need to put the ripper program on mem card as well and send the game data to a PC via the BBA.
Mod-Chip Method:
Direct boot all backups. Obviously this seems like the best method, and the cheapest (some modchips are now less than 20$) but your going to have to take the whole GC apart and solder at least 7 points. Many modchips have functionality for backing up games, and others can support it by burning the ripper program to a DVD and booting it. You still need a BBA to transfer the game data to a PC.
Due to the lack of a good no solder solution, my Gamecube gets used maybe twice a year. Original GC disks cannot be read on a PC, so you always need to activate the ripper program on the GC and then send the game data through BBA.
