Well swapmagic isn't to bad to use, but with memento you have to buy their special memory card which has a usb port built into it, you use a usb cable to hook this special mc to your pc, and then they have a firmware program that will put the firmware required to play a backup onto this special mc.
Once there is a hacked version of this firmware which can go onto a sony mc then the special mc will not be needed, as there is some elf files out of this firmware hacked, but i tested all 3 of them and all i got was a black screen and nothing started, it is quite hard to bypass the magicgate in the sony mc.
Once they work on these elf files some more they might eventually make it work, but till then this special mc is required as far as i know.
Also you have to patch a iso file of your game first before your burn it to a disc with their iso patcher which puts something into the iso file so that when you load the memento program and start game it looks for this certain something on you burned disc, kinda like adding a certain string in the iso file before you burn it, so that this memento can find this certain string and make the ps2 think it is playing an original game.
This memento only works on ps2's up to a certain version, which i think includes a few versions only in the slimline consoles, but all older bigger consoles will work with this i believe.
Hope this will help you a bit.
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