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Flicker 5 colors from 3

batari Basic DPC+ Demo

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#1 iesposta OFFLINE  


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Posted Sun Aug 24, 2014 2:54 PM

I will add to this post, so check back if you are following.
How to get 5 colors from 3 colors:

This is done in the batari Basic DCP+ kernel, but it would work in the original batari Basic kernel if you can have an asymetrical playfield and both missiles and quad size players.
The M and A are red playfield.
The 2nd P and Y are blue playfield.
It flicks between the red PF drawscreen and the blue PF drawscreen.
The A, P and second P are dim yellow 2 players (quad size) and both missiles (set to 4 wide).
Player0 is the A and the first 2 bits of the P.
Missile0 is the long third bit of the P.
Missile1 is the short center of the P before the hole.
Player1 is the end 2 bits of the first P and the 2nd P.
To blend the players with the playfield, it is set to show the playfield in front of the players.

There is a program called: flickerpicker.bin
The colors don't always mix like paint colors.
Here the red and yellow make a nice orange, but the blue and yellow do not make green, but more of a sky blue or light gray.
It looks a bit worse than the above photo of the TV screen. Also the first P is more yellow, the A is more orange. The M and the Y flicker the most.
It will also look a bit different system to system, and depending on how the Atari's color is adjusted and the TV's colors are adjusted.

The cat is a demo of both players making a multicolor sprite. This is rarely used due to flicker or due to using both players, but D.K. VCS uses this technique quite effectively.

The source and binary will be attached, along with flickerpickerntsc.bin

In assembly language you would just code an asymmetric playfield with mid-line color changes. That would give you five actual colors across without any flicker.

Attached Files

Also tagged with one or more of these keywords: batari Basic, DPC+, Demo

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