Isn’t it beautiful? There is something hypnotic about that watching that video game – Robotron 2084. The levels are all fundamentally the same, and the action always takes place in an open arena.

But later, the enemies start getting silly. Glowing circles, rainbow-color-changing enemies, and, my personal favorite, the number “2084” shooting stuff at you.

Some of these enemies actually take advantage of graphical artifacts from that era of computing, such as indirect color registers, which store color information outside of the screen buffer. By changing a single register, you change the color of every pixel on the screen. By running through a loop and changing this register, you create flashing and color change effects.

I like this aspect of graphics : Playing with registers to create a cool graphical effect.

Fun stuff.