i downgraded my PSP os to 1.50 & now my all Lucas games working vnice

Thank you Scummvm

Well i just meet the scummvm and i saw many topics about : Psp System version & Firmware so i checked my ver it says 3.40 of at the beginning it was 2.71 but my big brother updated from sony site. so i downloaded scummvm-0.9.1-psp ofc it did not worked. i saw i have to downgrade my psp system. B...