QUOTE (GameCop @ Jul 13 2008, 04:16 AM)

I understand that. But I said, what if you loaded a homebrew app into PS1 mode, so you can utilize the PS1 hardware to play backups off HD?
QUOTE
It's not likely to ever be possible to run PS1 games from the HDD. Not with HDLoader, HDAdvance, Toxic OS, or anything.
When the PS2 runs in PS1 mode, it's using its IO controller as the cpu. HDLoader (and variants) use that processor to run the drive emulation driver that's used to remap dvd calls to the game partition on the HDD. Also, PS1 games don't go through that driver for their drive access anyway, so even if the driver were running on the EE (which it isn't, and never will be because the EE is disabled in PS1 mode), it wouldn't work.
It's been gone over hundreds of times already. It's never going to happen.