No need for a real vmp converter.

[ShendoXT]

Upon testing the popsloader I figured out how to use self-made vmp file to be succesfully loaded.

It's simple really.
Replace the mcr inside the SCEVMC0.VMP, you don't have to change the header.
When you start a game press R and use pops from 3.00-3.30 firmware and your file will load without a problem.
(Be sure that you enabled plugin in the recovery menu)

I'm guessing that Dark Alex made loading of mcr from vmp without checking the vmp header, and upon saving popstation
does all the job and saves to .DAT.

When you want the vmp save back just use pops from 3.40+ firmware.

[Gamesoul Master]

Yeah, but how does one go about using an older version of POPS? I'm running 3.80m33-5. Since POPS is the same name regardless of version, wouldn't I have to keep replacing one version with another every time I want to import or extract a save?

And if he knows how to bypass the check on the vmp header, why didn't he just implement code in all his firmware versions to bypass the check in the first place so we wouldn't have to worry about a card reformatting itself?

I haven't tried Savegame Deemer yet (I will in a little while), but it seems like it may be another good alternative to this (seemingly) long method of handling saves.

[ShendoXT]

Use DAX's popsloader, with it you select what version of the popstation you want to use from the Memory Stick.

And if you don't have any older pops.prxes you can, google, uh dump them easily.

[Gamesoul Master]

Hmm... Thread's getting old, but it still contains valid information.

The problem with that technique is that it's as much work (even more, for many people) than the rest of the annoying/troublesome/lengthy techniques out there. There is a moderate group of modded PSP users out there who aren't really capable of *any* of these techniques (especially one like this) or don't like having to go through so much trouble all the time (CWCheat falls under that category).

This checksum crap still really bugs me. It's a damn checksum, it shouldn't be *this* difficult to crack. Rather illogical how Sony will put relatively easily-cracked protections on things that actually cost money, and put something that nobody can figure out on something as stupid as a virtual memory card on a video game system.

Can it really be that difficult to crack, or is there just that little interest from people who'd be able to do it? I guess it might be a similar situation to why nobody cares about downgraders anymore (which almost makes me hate the Pandora's Battery, because it made it pretty much a requirement for a potential modder to either know somebody with a modded PSP or pay money to somebody to do it).

I have to either start a new thread or revive one about this issue. I really want/need to gather as much known information about this checksum situation as possible. Posting on a bunch of major forums turned up zero results. I just want enough information to narrow down any trial-and-error efforts I may make into figuring it out. The more info I have, the less number of years it'll take me to figure it out... XD