i need alotta help

[whttabeach]

Next month I go back to school and my dormmates all own PS2's. I recently received a SONY DRU-510A for my B-DAY and I wanted to start backing up my games. My roomates liked the idea and want to do the same. We all have different model PS2s. I know mine is a US version 1 cause i bought it on launch day. My friends aren't sure what version they own and I understand it matters.

1) how do i identifly what model a PS2 is?

2) is there a chip that is compatible with all PS2 models?

3) best chip(s)? is there a site that compares the features of different chips?

4) DVD+r or -r? Once again is there a media that is compatible with all PS2 versions? Best Brand?

5) Is it true backups don't work online?