mirror of
https://github.com/dpeckett/arduino-appleii.git
synced 2024-11-29 13:49:21 +00:00
30 lines
923 B
C++
30 lines
923 B
C++
// Hook routines for the apple II monitor program
|
|
// Used to trick the apple code into working on this hardware
|
|
// Ideally should patch the ROM itself, will do in future.
|
|
void program_hooks(unsigned short addr) {
|
|
// hook screen scroll, monitor command
|
|
if(addr == 0xFC70) {
|
|
screenScroll();
|
|
PC = 0xFC95;
|
|
}
|
|
// hook cassette write commnand
|
|
else if (addr == 0xFECD || addr == 0xFECF) {
|
|
// Header length
|
|
cassette_header((addr==0xFECD)?64:A);
|
|
// Write Data Block
|
|
cassette_write_block(read16(0x3C), read16(0x3E));
|
|
// Emulate counter behaviour
|
|
write16(0x003C, read16(0x3E));
|
|
PC = 0xFEF5;
|
|
}
|
|
// hook cassette read command
|
|
else if (addr == 0xFEFD) {
|
|
// Read Data Block
|
|
boolean success = cassette_read_block(read16(0x3C), read16(0x3E));
|
|
// Emulate counter behaviour
|
|
write16(0x003C, read16(0x3E));
|
|
if(success) PC = 0xFF3A;
|
|
else PC = 0xFF2D;
|
|
}
|
|
}
|