Sony have confirmed that the reason Skype will only work on the PSP Slim & Light is due to memory constraints. The original PSP (PSP-1000) has 32MB of memory, whereas the newer Slim & Light model (PSP-2000) has 64MB. Sony did study the possibility of supporting Skype with PSP-1000, however they had to give it up due to the smaller 32MB of memory.

Sony announced at CES today that Skype will be made available for the PSP Slim & Light. By adding the Skype logo to the XMB via a firmware update, users will be able to access full Skype voice functionality including the use of Skype Out / Skype In, as well as access to the account admin functions.

Before you ask, the reason Skype will only work on the PSP Slim & Light (and not the original model) is due to memory constraints. The original PSP (PSP-1000) has 32MB of memory, whereas the newer Slim & Light model (PSP-2000) has 64MB. Nick Sharples had the following to say.

“Although PSP-1000 and PSP-2000 are identical in basic functions, there are differences in hardware specifications to some extent and, for that reason, PSP-2000 may differ in features from PSP-1000. We had studied the possibility of supporting Skype with PSP-1000 but had to give it up because of the smaller size of main memory on PSP-1000 series.”