My sixth Atari 2600 program 🎮 explores the Playfield 🟦, its features, and how to master it for creating interactive graphics ✨.

After understanding how the Player, Ball, and Missile elements work, I have now dedicated myself to learning the last major concept of Assembly programming for the Atari 2600, which is the Playfield.

An interesting feature of the Playfield is its ability to be mirrored on the other side of the screen. To better understand this, imagine that on the Atari 2600, the visible screen area has a virtual central horizontal division. So, when working with the Playfield, everything drawn on the left side of this virtual division can be repeated or mirrored on the right side. From what I understand, it is possible to "bypass" this rule, but I haven’t reached that stage of learning yet.

The Playfield fits 40 pixels on the screen, but only 20 are unique since the 20 on the left side are either repeated or mirrored on the right side. The Playfield drawing is controlled by the PF0, PF1, and PF2 registers, along with CTRLPF. The first three determine the shape of the drawing, and the last defines how the drawing will be configured (repeated, mirrored, etc.). The Playfield color is set by the COLUPF register, but depending on the CTRLPF configuration, it is also possible to use the Players' colors.

In short, this learning phase was quite fun, and once I got the hang of it, working with the Playfield seemed simple. Now that I’m familiar with the basic graphic elements of the Atari 2600, I believe I can start developing more interesting and interactive exercises.