That sounds plausible.Twoflower wrote:This actually sounds quite reasonable to me; according to Pete Rittwage's site, the only copy-protection present on the BT III disks should be the codewheel. All the disksides should be copyable. What sense does it make to do two different versions, when you could make an interpreter for almost everything in the Apple II version?Darendor wrote:Track 15, sector 14 has the text: "PRODOS ERROR # [...] HAS OCCURED!"...
It seems to me PRODOS isn't a copy protection or code scrambler but rather...the DOS from the Apple systems.
I'm pretty sure that you can find the exact same datastrings you find on the C-64 disk on the Apple II disk. This might also give me an opening to the images? Are these stored in some kind of native Apple II graphics format?
So far i've managed to find out that the images are stored as sequential commands, not as a bitmap image. I believe the image is plotted in vertical sequences from the upper left corner, and all these sequences are ended with byte #$FF. Removing parts of the image (counting the divider #$FF bytes) from the end causes the image to lose animation-frames and if you continue - parts of the image. I will investigate this more thoroughly later.
I'm not sure but I think I remember the BTIII disks back in the day being bootable on either the C64 as well as Apple II. This explains why.