Originally Posted by Leffmann
IIRC you can only get to a limited amount of Blitz's internals, and with this type of 8-way scrolling, as you know, you need full control of the graphics hardware. You may have to implement the whole graphics engine as a set of Blitz commands and tell Blitz to stay off the hardware. I'm not sure the latter is possible, but it's worth looking into.
I can provide bob and sprite routines as well, that go with it. In fact it really has to use its own bob routines anyway. I have written the scrolling routines into an AMOS extension before, all it needs to work is a call to "Copper Off" to turn off AMOS's copper list generator. I presume you can turn off the copper list in Blitz, too. The scrolling routine will write an appropriate copper list for you if you provide it with some Chip RAM to store it in, then all you have to do is load it into the copper list hardware pointer every frame.
Currently it works with AMOS screens and AMOS icon banks, but if I can get some documentation of how Blitz stores these things I could easily modify it.