Almost.

1.5 = Good for homebrew, not much else.

2.0 = Not good for homebrew, but has a web browser and other limited functions.

2.01-2.71 = Not good for homebrew, but can be upgraded to 2.71 to downgrade to 1.5

2.80 = Can be downgraded, but it's less safe.

2.81 and over = No homebrew, no hacks, no downgrader. Stay away.

2.71 SE/3.02 OE/3.03 OE = Store PSPs don't come with these, but they are hacked versions of firmwares that allow for homebrew access, with the other functionalities of the firmware. For example, 3.03 OE is 3.03 with homebrew and a bunch of added features, while 3.03 by itself is the worst for homebrew, as it has no hacks, no homebrew, etc. This is my favourite.

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