Some PSP games were not designed with portability in mind. They don’t let you save your game progress within lengthy quests or battles.
For this reason, PSPStates was developed. It’s a plugin created by Dark_Alex, the legendary PSP developer, to be used for the PSP. It lets you save anywhere within a game, where you can resume it later.
However, there are some limitations to this plugin:
PSP Slim & Lite only is supported (PSP-200x), running 4.01 or 5.00 M33 custom firmware. Other M33 versions are not supported. Official firmware are not supported.
It doesn’t work in POPS (PSX games) or vhs.
In order to make it work for UMDs or ISOs in normal mode, you need to flash a certain file.
There could be other limitations.
That said, the plugin works perfectly in ISOs running in M33 mode.
More information is here:
Download from here:
PSPStates for 5.00 M33
PSPStates v2 for 4.01 M33
Detailed instructions are found in the readme.txt inside the download file. The plugin is experimental in nature, so it’s not guaranteed that it would work in all cases. I hold no responsibility for any harm that might be caused by using this plugin.