Few words about changes made: first step was disassembly of main file with code and other things, like music data. It took couple days to find all locations where should use labels, proper sizes and similar (what made me to start thread about disasm. troubles). Org. code is done for fixed RAM loc at $30100, what is not compatible with hard disk drivers or Falcon. So, I rearranged game's RAM usage, and it is now fully relocatible. Was able to achieve that work from floppies on STEs with only 512 KB RAM (is there any such ?) by using Desktop workspace for game - what is wasted space in case of AUTO run.
Of course, there is added STE HW scroll code, what required several other changes in displaying routines, on about 100 places. Before all it needed to replace Timer B with Timer C for music generation, since Timer B is necessary to change scrolling at proper screen positions - after 16 static lines, and bottom 32 lines are static too. Final step in it was adding own joystick/keyboard reading code, because used TOS routine is just too slow, and that made sometime ugly screen jerks (Timer B IR delayed 1 line because slow TOS ACIA routine) .
One smaller error during it gave me idea to improve demo a bit - so it now goes thru level 1 in 8 steps instead starting every time at level begin.
Lot of time was spent on fixing game's nasty anti-hacker tricks, which made it crashing when code length was changed. I think that there is still couple in, but for segments where I did not change code length. There is Falcon PSG patch too (less shadows on Falc.) .
Future plans: this uses not blitter, and I don't think that it is really necessary. Would make it working little better on plain STE, but not working on TT . It works with current code at about 35 fps on 8 MHz STE, what is not bad. On Falcon with VGA monitor it is 60 fps, and a bit too fast then.
In PAL mode pretty well playable and with stable scroll speed. I will add some intro, like original one, but with DMA music playback.
PP, May 27 2015.