Does anyone know what needs to be done to write a program using the Softcard
which sets the Apple II into graphics screen mode and provides an 8K display
window at $2000 similar to what GBASIC does and sets the Apple II back to
text mode when done. The following Aztec C CP/M 80 program doesn't work and
the code is loaded above an 8K memory hole above HGR1 so it doesn't crash
either.
See the function setcrtmode() in the listing below.
The Softcard manual says CP/M relocates some of the Apple $C000 but it isn't
specific what these might be or how one might use them.
If GBASIC can do this I can do too. But obviously not without help.
This seems to be a simple problem. Using a graphics library doesn't seem
needed. Switching to 6502 mode and then back again doesn't seem needed. But
perhaps I am minimizing this.
Code below:
BEWARE! DOES NOT WORK!