HBL Revision 99 comes with some major improvements. First, the dreaded “sceCtrlPeekBufferPositive” (the function that basically makes emulators run at full speed) should now be available on all models of PSP. Remember, it wasn’t correctly working on PSP 1000/2000/3000 on 6.20. Although there are still a few differences in the quality of syscall estimations for these models on this specific firmware, this major function is now working on all models, and you should all be able to enjoy full speed on your favorite emulators. This makes the “”override_sceCtrlPeekBufferPositive” obsolete, and if it hasn’t been done yet, this option will be removed from HBL in a future update (since it doesn’t do anything anymore).

This version also fixes most issues with the PSP HOME button, thanks to a patch by Nymphaea. It finally allows to run HBL from the memstick on a pspgo, and should fix the issue with controls introduced in R97.

I haven’t fully tested this release, but it’s been tested by a few people already, so I believe it’s good to go. For those who ask, R98 was released a few hours ago, but had a bug that prevented it to work correctly on a 6.20 PSPGo

Half Byte Loader FAQ

[SPOILER]What is Half Byte Loader?

Half Byte Loader (a.k.a HBL, a.k.a the Valentine Project) is a tool that allows to run fan-made games on the sony PSP. HBL is designed to run on the Sony PSP on official firmwares (OFW).
Does HBL work on my PSP XXXX with a firmware Y.YY?

HBL works on ALL models of PSP, and ALL firmwares up to 6.20 included. This includes the PSP Go, and is independent on where you bought your psp. HBL does not run on firmware 6.30 at the moment.

How do I install it?

You need an unpatched patapon2 demo, my crafted savegame, and HBL itself. To run, just launch patapon, load the crafted savegame, then press the RTriggrer twice. You’ll find dozens of tutorials on the internet
I installed HBL correctly, but when I try to load the savegame, it tells me the data is corrupted

You either have firmware 6.30 (or above), or you downloaded a patched version of Patapon2. Make sure you have OFW 6.20 or less, and re-download the Patapon2 Demo. Do not download this demo from the Sony PSN, as their version has been patched.
I installed HBL correctly, but it just freezes and my psp shuts down when I press R

You installed HBL wrong. Try to get it again from a trusted source, for example, the official download page. You will also find autoinstallers on the net that do everything for you, try that. Most likely, this is because you put some files in an incorrect place, or you got an old version of my crafted savegame. 100% of the people who asked this question to me ended up realizing they were doing something wrong, so don’t start thinking your psp has “some special security”.
What is the Difference between HBL and a Custom firmware (CFW)?

HBL allows you to run homebrews on a PSP that has an official firmware. A Custom firmware is a piece of software that is usually flashed on your PSP’s flash memory. A Custom Firmware patches your PSP firmware to run unsigned software. Usuall CFW allow users to run plugins, isos (backup of official games), homebrews, and allow you to customize your XMB (psp menu). HBL “only” allows you to run homebrews.
Does HBL run isos ?

OK, but can HBL run a homebrew that would load ISOs?

In theory, maybe. Practically, all teams who have tried to code such a tool so far have failed. This is because HBL runs in user mode, and iso loading most likely requires to bypass some protections that live in the kernel mode.
Can HBL load PS1 games?

Not for now. We don’t know if it is possible yet.
What’s the big difference between Kernel/User mode anyways?

To make things simple, let’s say that the User mode allows you to do limited things with your psp, like running homebrew games. Kernel modes gives you total control of the psp.
Is there a list of homebrews that can run with HBL?

There is no definite list yet. HBL is still a work in progress and a compatibility list would be made obsolete every week or so. However you can have a look at $k0 AdvancedPSP.tK $k1 • View forum - Half Byte Loader to get some names of homebrews
Team XXXX say they have isos running (or a CFW) through HBL, is it true?

So far, all these kinds of announcements have been fakes. Be sure that if/when this happens, it will be on the front page of major PSP sites.
Why do you waste your time with a homebrew loader when you could spend it finding a kernel exploit and creating a CFW/HEN ?

Finding an exploit is difficult. Finding a kernel exploit is even more difficult. Half Byte Loader is the result of months of work, and if you can’t appreciate it, well too bad for you. I’m sure better solutions will come in the future, but for now you should be patient and accept what you get.
Which version of Daedalus (the Nintendo 64 emulator) works on HBL?

I don’t know exactly. I personally use Daedalus R13, but it does not offer the level of playability I expect from an emulator. The team behind deadalusX64 is working hard on new releases, and I believe they are making efforts to get their emulator compatible with HBL, please contact them directly
Revision 85 was better than the new ones, can’t you simply make revision XX with the compatibility of rev 85?

No. The only issue with newer revisions is that sometimes you can’t exit your homebrews. If that annoys you, edit the file hbl/hbl_config.txt with a text editor (such as notepad) and replace return_to_xmb_on_exit=0 with return_to_xmb_on_exit=1. You will then have the behavior of r85, with the new features of new revisions.
GPSP crashes when I exit

That’s a known issue, please check the list of issues before reporting a bug.
The sound is weird in picodrive

change your settings for sound in picodrive to 44000Hz
Can you make my favorite game work in HBL?

We take those requests into account, but usually the best is for you to contact the homebrew creator and ask them for HBL compatibility. HBL runs in a very restricted environment, so we will never get 100% homebrews to work, but sometimes it’s just a matter of changing a few function calls in the homebrew itself.
I can’t quit homebrews, the “home” button doesn’t work!!!

This is a known issue in HBL, but there are a few workarounds. First, try to press simultaneously select and start in the homebrew, to see if it takes you back to the HBL menu. If this doesn’t work, and if you don’t mind running the patapon demo all over again, you can set the variable return_to_xmb_on_exit=1 in the file hbl/hbl_config.txt. This will fix the home button issues, but you can’t go back to the HBL menu when you quit a homebrew.[/SPOILER]

Source- wololo