|The Apple II saw many
generations of it's hardware, from the early Apple II to the final
Apple IIgs the hardware remained mostly compatible, however the
harfdware was heavily upgraded, moving from a 4k 6502, to a 8mb 16 bit
The most curious thing from our point of view is that the Apple II used 3 generations of the 6502, and it's the Apple IIe with its enhanced 8 bit 65C02 we'll cover in these tutorials
|There are many versions of the Apple 2, we're only going to cover the Apple IIe in these tutorials.
|The Apple IIc memory map is pretty typical.
We'll use Graphics Mode, and Page 2 - this means for our purposes the area $0C00-$3FFF can be used for our main program code.
Notice that the area $C000-$FFFF allows us to access the hardware...
Each "Port" has a different purpose, but rather strangely when we want to do something like set the graphics mode, we write ANY value to the graphics port... the value makes no difference!
|Writing any value to these memory addreses causes the hardware change.
For example, to change the system to graphics mode:
sta $C050 ; Text off
sta $C052 ; Mixed Mode off
sta $c057 ; Display hires
sta $C055 ; Hires screen 2