Story by: Johnny Minkley, Eurogamer.net

The next iteration of Sony’s PSP handheld will feature a sliding screen, will no longer carry a UMD drive and will allow shoulder button-only games to be played when the screen is in its ‘closed’ position.

That’s according to a development source close to Sony, speaking to Eurogamer on condition of anonymity. We first broke the news of a new update to the system late last year, revealing that PSP-4000, the third incremental hardware revision of the console, is planned for release later this year.

While Sony has refused to comment so far, further rumours have emerged in the past week claiming that 4000 will represent the first major overhaul of the system, with a sliding screen added and the UMD drive removed.

Our development source today confirmed these reports, adding: "The screen is basically the same as the one in the 3000 – except it slides." When ‘closed’, we were told, the screen won’t cover the entire face of the console, but the unit will be "significantly smaller in width" as a result.

With the console in its ‘closed’ state, most controls will be inaccessible. However, our source claims that games which use the shoulder buttons exclusively – such as LocoRoco – will be playable, as these inputs will still be accessible. It’s expected that the unit can also be used for media playback in this configuration.

Eurogamer further understands Sony is approaching developers for ideas for games that only require the shoulder buttons.

Sony said this afternoon it does not comment on rumor or speculation.