I recently came across the and decided to test it out on a custom firmware PSP (5.00 M33-6, as the name suggests).

If you downloaded this "MEGA-PACK" in 2009, you were likely on a PSP-1000 (Fat) or PSP-2000 (Slim) with a Pandora battery ready.

The string "PSP MEGA-PACK -184 ISO-CSO 73 -Minis-- -5.00m33-6-l UPD" refers to a comprehensive digital collection for the Sony PlayStation Portable (PSP)