Question about JagCD

[Cyrano Jones]

Hi

 

Just a thought.....

 

From what I understand, the Jag skips an audio track, then loads a binary from session 2, checks a random block from that binary is encrypted, then runs it. I understand it doesnt check beyond the data track, if it did, we'd have to encrypt those, meaning CD-Audio wouldn't work.

 

Meaning making CD's is a royal pain in the arse....

 

Is this possible:

 

Make an encryted CD that loads an extra unencrypted track (stored as audio data) of a fixed length, (eg, $200000-$4000) so that the TOC is always the same each disc, and then jumps to $4000 to run it?

 

That way, we could have a standard imagefile and we could just insert our data file into it as the audio track. No messing around, no encrypting (more than once).... bish bash bosh... done?

 

Now, I'd be really interested in helping with that, except I don't have a JagCD Someone who does maybe could comment?

[SCPCD]

hmm

I think that this could work.

 

And what about rewrite the encrypt algorithme on a PC and use directly CD image ?

 

[Cyrano Jones]

I'm up for helping with this any way I can, but I don't have a CD-Rom... Got a Skunkboard here.

 

But before it loads it could put up a bitmap saying "Jagware/Reboot Universal CD Loader" or something, so if others use it we get the credit :-)

 

(And don't give out any source for the loader, just the completed image, and a tool to inject the unencrypted binary)

[Cyrano Jones]

The way I'd do this is:

 

Have a PC app thats got the image of the loader internally and asks for an unencrypted binary (of any length, but load/run at $4000). It pads and converts it to audio data then injects that into the image it has, and dumps out a .NRG file.

 

Simple, easy and quick.

 

Maybe even ask for a load/run address, put those infront of the binary file as a header. Have the loader load it at, say $4100 always, then copy a routine down below this, and relocate/run it. That way *any* binary/cof/bjl file could be put on a cd-rom as long as it loaded at $4000 or above.

 

 

If we do this can we please call it "Jaguar ULS" :-)

[Cyrano Jones]

If you wanted to be really clever, you could split it up into say 200k chunks, so each 2mb image is 10 tracks.

 

checksum each track. Save each track 5 times.

 

On loading, if an error was encountered, go to the next available track for that chunk and try again.

 

This could seriously reduce "bad" disk burns.

[Orion_]

I had the same idea when I was working on the JagCD, but never had motivation to test this (I threw away too many cd-r before having a correct encrypt method ^^)

Another idea was to make a boot cd, that could load an unencrypted cd (there is a cd_switch function)

but I don't know if it recheck the cd when you switch

 

[Cyrano Jones]

Well, that won't work, but I've got another idea ;-)