Day 10 was kind of a dud. I was more worried that I was losing my main OS drive on my computer, so I didn't do a learning challenge. (Everything's fine, AFAICT).

Day 11 and I decided to try something a little different:

This is a reproduction cartridge of the venerable (and awesome) Mac/65 cartridge from Optimized Software Solutions; makers of some of the best development tools for the Atari. (Available here.) I have it plugged into an Atari XEGS (with some of the best composite video of any Atari machine).

What I was trying in this iteration was to see if I could copy the data in the memory locations for one of the controllers over to the X and Y registers. So the X register would hold the value of the joystick and the Y register would hold the value of the joystick trigger. This was mimicking some of the input / output routines that Assembly Lines was doing with the Apple machines that I wanted to see if I could replicate in some fashion.

Simple? Yes. Pointless? Of course.

Fun? You betcha.

What you can't see in these images is the (excellent) DDT debugger iterating through the code as I move the joystick. I was only able to capture the trigger getting pushed and released; and that seems to only be showing the JMP instruction at the end.

Not a whole lot learned in this iteration outside of some of the memory mapping of the Atari (the book in the left-hand corner is "Mapping the Atari" from Compute Books, which was the de-facto memory mapping of the Atari machines. (If you want to hear how Ian Chadwick mapped out the Atari check out the Antic Podcast interview.)