DanBoris' Tech Blog - Ball Horizontal Correction

[RSS Bot]

While studying the score counters I was having a hard time figuring out how the score was credited to the correct player, it seemed that misses on the left side where scoring on the left side instead of the right. Turns out that I had a mistake in an earlier section, Ball Horizontal Control (Part 1). Turns out that I had the /HIT1 and /HIT2 counters reversed, the circuit should look like this:

 

 

This is the proper description of how this circuit should work.

 

The flip/flop H3 is used to control the direction of the ball. When the ball hits the left paddle, /HIT1 will go low, which will set pin 8 of H3 high, indicating that the ball should now move right. When the ball hits the right paddle, /HIT2 will go low, which will set pin 9 of H3 high, indicating that the ball should now move left. When MOVE is low, Aa will be 0 and Bb will be 1 which keeps the ball stationary.

 

When L and MOVE are high, Aa will be 1 and Bb will be 1 which causes the ball to move left. When R and MOVE are high, Aa will be 1 and Bb will be 0 which causes the ball to move right. We will discuss the function of the CLK input to H3 in a later.

 

The L and R signals indicate which direction the ball is currently moving and this is important to understanding the way the score counters work.

 

 

http://www.atariage.com/forums/index.php?a...;showentry=1744