You don't need to scroll through an on-screen keyboard. Plug in a standard USB keyboard to type in custom codes from websites like GameHacking.org.
Pre-loaded with codes for over 2,000 games. codebreaker+v101+ps2+iso
For physical consoles, Codebreaker is often used alongside softmods like or Open PS2 Loader (OPL) : You don't need to scroll through an on-screen keyboard
On a real PS2, you would physically swap the Codebreaker disc for your game disc. In PCSX2, you must perform a : 000 games. For physical consoles