>In Fast Food, how did they make the letters for You're
>getting fatter? Those ain't playfield graphics.
A 48-pixel-wide sprite. Same thing as the six-digit score routine,
except using static graphics instead of dynamic digits, and more height.
>In Space Invaders, how do they do it? I'm guessing
>the invaders are drawn with player graphics, but how
>do they move the rows over? Also, if I hold reset
>while turning on the power =:-D I get two missiles,
>and the invaders get two missiles, and they all move
>independantly. Where did it come from?
The invaders are player graphics, of course. How they move the rows
over is just to hit RESP0 and RESP1 at different times. As for the
lots-o-missiles... all the missiles are actually the ball. The invaders
get two missiles, both drawn with the ball (since they're separated
vertically), and you get two missiles also separated vertically. Your
missiles and the invader missiles are each drawn on alternate frames,
causing flicker.
>In Missile Command, how do they draw all the missiles
>and their trails? My only guess is with ball
>graphics, but I can't see how--I thought you were
>limited to one ball on screen at a time. Likewise,
>Pitfall with its swinging rope. It changes color
>depending on the scan line, so I'm guessing ball
>again, but how?
Missile Command's missiles are one of the players, cloned if necessary.
Two sets of missiles are drawn by flickering them on alternate frames.
>In "Asteroids", all those asteroids and the ship with
>no flicker until you get over (I believe) 6 asteroids
>on screen.
No flicker? Look again, bub. They flicker as soon as you turn on the
system. Notice how all the upwards-moving asteroids move at the same
rate, and so do all the downwards-moving ones? The upwards ones are all
drawn on one frame by reusing one player, and the downwards ones on
alternate frames in the same way.
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