Full exploit can be found here :

basics

To make a long story short, the exploit allows anyone with a memory card and a valid, legal PS1 disc to hijack the boot process and run any piece of code.
Absolutely no modification to the system is necessary to use the exploit. All one really needs is a way to send the files to the
memory card to enable the exploit.

Technical

PS1DRV parses a file called mc0:/BXDATA-SYSTEM/TITLE.DB (the X represents the PS2's region code) to load graphic parameters for the PS1 game that was loaded from the disc drive. There is a catastrophic buffer overflow in the parsing routine that allows one to overflow the stack and execute arbitrary code by rewriting the $RA register.
If we load up our own TITLE.DB, with an entry for every PS1 disc that we want to trigger the exploit, then we can take over the
PS2 boot process as soon as the disc is recognized and PS1DRV is executed.

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If you find another LEGAL exploit , feel free to add it to this topic.

Does it work with version 12 or 13 slim systems?

the link doesn't work....can some one give a new link or something i want to read more on this......can you play backup games with this trick

Here's a tutorial....
http://exploitstation.com/articles/a...xploitUSB.html
(codebreaker can also be used)

When you get this working and use CSL(Cog Swap Loader) use this procedure to boot backed up ps2 games...
1. boot with exploited memory card and trigger disk
2. select CSL from menu, (may have to navigate a bit)
3. hit the open button and insert an original ps2 game
4. let the game load(just listen until the disk stops making noise/stops)
5. Press x and let the game spin, upon finishing a USE COG SWAP will appear
6. Use your loading device(fliptop/slidecard) and insert backed up media
7. Press x to load the game

This exploit works with all version 1-10 systems. It is in fact for playing backup games primarily, but also has other executable files you can use(google .ELF files). Sony realized the exploit and fixed the Ps2 slimlines, therefore only version 1-10 systems will work.