Apple I Programming
Here are a few simple tips and programs for those interested in programming the Apple I:
To print to screen:
The above snippet relies on the Echo subroutine in the Apple I's ROM. All you need to do is load an ASCII value into the accumulator, then call that subroutine.
To read a character:
This subroutine loops until a key is pressed, then loads its ASCII value into the accumulator. It is not dependant upon the Apple I's ROM. KbdRdy and Kbd are in the 6821.