? play PS1 from HDD...

[l_oliveira]

No, not the ata patching function of the chip.

If i remember correctly there was an elf that writes a special mbr to the hdd.


Rgds.

In 2003 ? I doubt it.

HDD MBR is Magic Gate encrypted and while at it also it has a custom header which is checked by the BIOS before it even attempts to send it to the MECHACON for decryption.

So nothing but a true MBR sector would work there.

[fresh]

I updated my last post and the elf writes a lba48 mbr.

[l_oliveira]

I updated my last post and the elf writes a lba48 mbr.

MBR as Master Boot Record (what allows the hard drive be booted from) and nothing we do with the HDD on the PS2 currently uses a MBR. Are you sure you don't mean 48bit ATAD no ?

And even so, the only SONY things that use the MBR are HDD OSD and PSBBN.

[fresh]

Sorry, it was too late for me yesterday.
I mixed some things...

[averybomb1]

maybe not go into ps2 mode, maybe be running it and be able to go back to ps2 like an emulator like snes station, pgen or FCE-Ultra

[dlanor]

maybe not go into ps2 mode, maybe be running it and be able to go back to ps2 like an emulator like snes station, pgen or FCE-Ultra

Effectively that's how it works when using ffgriever's PS1 emulator PS2PSXe, which is a PS2 application launched from another PS2 application, and able to restart that GUI shell if you exit from the emulation using a special gamepad button combo. (Just as with most other emulators.)

Normally this will restart the PS2PSXe GUI shell, but by ELF replacement it's easy to make it relaunch uLE instead, for those who want to use it as the launch GUI.
That's what I do myself, using uLE to launch game specific RadShell instances which launch the emulator with proper PS1 VMCs chosen for each PS1 game.

Doing similar things without emulation (from real PS1 mode) is strictly impossible, so don't bother asking for it.
(When in PS1 mode the console has no way of just switching to PS2 mode. That requires a full system reboot.)

Best regards: dlanor

[averybomb1]

alrighty well thank you very much, but um, i still do think it would be possible but instead having opl as it's backround runner. I mean they have gotten this far. But for the best solution to playing backup psx games on ps2-just go with psx launcher

[dlanor]

alrighty well thank you very much, but um, i still do think it would be possible but instead having opl as it's backround runner.

Yes, of course it would be possible. I said as much in my last post, where I mentioned how I trick the emulator into relaunching uLE at exit from an emulated game, instead of relaunching the PS2PSXe GUI shell program. The very same trick could be used to have it relaunch OPL at exit from an emulated game.

I simply replaced that GUI shell program with a tiny elf I made which just reboots "mc0:/BOOT/BOOT.ELF", which is my main uLE elf. This way it will relaunch uLE in exactly the same way as for a new boot. (That would not be the case if I had used a copy of uLE as replacement elf.)

Btw: Some variation on such relaunching is how ALL 'background shells' work on the PS2 for PS2 games as well. Since it is impossible to keep an entire GUI shell in RAM during the running of a game, the shell is relaunched as needed from a small relaunching stub 'hidden away' in some RAM location not usually used by games. And if any game does use it, then that game breaks the shell relaunch compatibility. That's not an issue with emulated PS1 games though, since they run in a virtual RAM space, and this only uses a small part of the PS2 RAM.

But as things stand right now only a minority of PS1 games run really well with PS2PSXe (= no glitches at all, neither in graphics nor audio nor speed), and while this remains the case no one is going to do the strenuous work of coding new versions of OPL to handle PS1 game launching through PS2PSXe.

So yes, it is possible, but no, it's not going to happen for this stage of the PS2PSXe emulator.

If/when ffgriever updates it again, to eliminate some remaining problems (like sound effect termination issues), then it might happen. But not now.

Best regards: dlanor