120Gb USB HDD and USB extreme on the slim line PS2 (UK version 12), no modchip needed. However I've found games from EA won't back up using this method. I've tried using my originals of both SSX Tricky and Burnout 2.
do you not need a new case like for the ps2? not the slimline one i mean if u wanna disc swap its modchip for me all the way on me xbox anyways i dont have pspoo ;~)
With the old style ps2 you remove the front of the dvd tray to allow you to swap the disc without pressing the eject botton.
New 'flip-top' slim line ps2 uses what is refered to as a slide tool, though with revision 12 you may have problems as sony have altered the lid slightly.
ive chipped numeruos ps2's
to make life easier use kynar wire on most of the points except ground and live
also try and keep the + _- as short as possible.
if not confident on soldering the new dms4 is out