> I think it would be easier for both the game owners > and me to let me help them to break some individual > features in copies of their OAKCDROM (UPC, subchannel) > and then ask them whether it made their game fail. > > That way, I only have to send a debug script or file > to modify their OAKCDROM driver and no physical game > CD or DVD have to be sent around. > > When we know which of the 2 features (or maybe others) > are relevant for the copy protection, only then can > we start thinking about implementing those features.
I would take the opposite approach. I would start by adding the standard features we know are missing in Jack's drivers and see if it fixes anything. Those features should be there anyway, and (at least to me) it doesn't really matter if they are actually used by existing applications or not. If that doesn't fix the copy protection then some further investigation would be required. You can either do this by breaking things or by monitoring the calls that get sent to the device driver. I admit it would be kind of nice to know how the copy protection works, if for no other reason than to try and avoid something like this again in the future. I think the first thing to do is fix Jack's driver to make it a 100% driver, not try to figure out ahead of time whether making it a 95% or 100% driver will fix a specific problem. As you've also pointed out with the DOSBox code, sometimes there's enough ambiguity in the different specs (like the between the SCSI commands and the MSCDEX spec) that it's not always clear what the correlation is. For example, "Audio Sub-channel" vs. "Audio Q-channel" -- I'm not 100% sure what the difference is and the existence of the sub-channels isn't related to whether the CD contains audio or not. It could be that Jack's implementation of one of the (supposedly) working IOCTL calls is somehow faulty in some respect and is returning incorrect data. I doubt that's the case, but it could be. I know I get confused when reading the different specs and looking at specific implementation code from others and wondering if they really did it correctly or not. _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
