Custom firmwares for the PSP has been since 2006, when Dark_AleX did a proof-of-concept firmware based on the 1.50 version. He added some extra functionality like autorun an homebrew, a limited recovery mode and so on.

The knowledge gained on hacking the 1.50 firmware, made it possible for Dark_AleX to release, 3 months later, the famous 2.71 SE firmware. That firmware was awesome at that age. In fact, most of hacked PSPs, were still running the 1.50 version + devhook, to emulate a 2.71 from the memory stick. With this firmware, everyone could update to 2.71, to get all the additional features, like the web browser, rss reader, and still can run homebrew (and pirated games). This release permitted to run compressed games from the memory stick, in CSO format. A great breakthrough!

Still 3 months later, Dark_AleX released the 3.02 OE firmware. Also this firmware gained an huge success: it permitted to use the internal Sony Playstation emulator!

How to update the PSP custom firmware:

Since the 3.90 M33 version, it is possible to update the custom firmware directly from the "network update" menu.

If you have a previous version, follow this steps:

1. Download the most recent CFW version from dark-alex.org (In this example is 5.00 M33-6)
2. Unzip the CFW that you downloaded from dark-alex.org (for example 500m33_6.zip), and place it in \PSP\GAME\
3. You will have a folder like this: X:\PSP\GAME\UPDATE\eboot.pbp
4. If you have a network connection, it will download automatically the needing files, otherwise:
5. Download the original 5.00 version from Sony
6. Rename the file as 500.pbp and place it in the same folder of the update

Now, an update screen will appear, and you are done!