Which is original between the old and slim psp

The differences between the original PSP and the slim PSP are mostly cosmetic. The UMD tray is no longer spring loaded, the memory stick slot opens differently. The two technical differences between the two that I can think of are that the slim doesn't include the IR port anymore and DOES include video-out capabilities. The weight difference doesn't hurt either, though I didn't really notice the size difference as much.