How do I play PS1 games through my PS3 to my PSP? I heard that's possible.

You can download PS1 games to your PSP via your PS3 from the PS Store.

There's also Remote Play, which links up your PS3 and PSP and I beleive you can do what you're after doing this way. I'll let other people expand on that though, I'm not 100% sure about it.

Oh no I want to play my PS1 games I already have on disc. Is it possible to save PS1 games on the HD?

This is a fairly old source but by the looks of it you can still "stream" your PS1 disks onto your PSP. From what I read that's only possible via Remote Play.

I'm not sure if you can copy games to the HDD from the disk though, and I can't really find anything useful online to help you with that sorry.

I'm pretty sure only Ps1 games that are downloaded from the Store can be played via Remote Play. I don't think it's possible to do it with a disc.

That's strange, I've heard you can put the disk in the tray and then load it via RemotePlay on the PSP. I've only heard mind, but I'm like 60% sure that was one of the great points of RemotePlay.

Yes, I can confirm you can do this, I did it just the other day with Tekken 3. You just gotta have the PS1 disc in the drive.

Oh ok. My bad. I don't have any PS1 games so I could'nt test it.