Your assembly code can just use the Color BASIC ROM's POLCAT routine to access the keyboard, if you like. But it has some limitations, and does a lot of processing you might not need. Today we explore exactly what's required to access the hardware directly to see what's going on with the keyboard. As a bonus, we go over the mysterious PEEK(65280), why we have to check for two values when querying a single joystick button, and how the joystick buttons cause bizarre conflicts with keyboard polling. Wow, I can't wait to watch this video. It sounds cool!

Download a copy of the keyboard visualizer: https://cocotownretro.wordpress.com/2...

Previous video on directly polling joysticks:    • 5 shocking joystick secrets! | Asm Ad...  


00:00 Intro
01:47 BASIC's ROM keyboard routine
05:04 Querying keyboard directly
07:02 Keyboard Visualizer
10:33 A look at the code
15:27 Joystick button interference
18:11 Mysteries of PEEK(65280)
24:34 Closing