This is great: thanks for sharing it. In 1983, Compute! magazine published yet another article on these opcodes: https://www.atarimagazines.com/compute/issue41/

This is great: thanks for sharing it. In 1983, Compute! magazine published yet another article on these opcodes: https://www.atarimagazines.com/compute/issue41/Extra_Instructions.php https://www.atarimagazines.com/compute/issue41/Extra_Instruc... . Now I can finally understand the why, not just the what.