Destroy All Humans 2600

Atari Dogs · March 15, 2009

I have been working on a hack based on the Destroy All Humans! franchise. If you don't know, it is basically about a bluish grey alien sent to earth to collect human dna to save his people and destroy a bunch of stuff. I hacked Pigs in Space. Sure it's not the best game, but it will do for now.

I still need to fine tune the colors. My kids are helping me with what they should be. I am having a lot of trouble with Gonzo on the Space Invaders type screen. I wanted to change it into the aliens boss, Pox, but the eyes are in the wrong place the turning around makes it more complicated. Maybe I need to get some graph paper and try to figure out the design. Making a flying cow head may also work.

Where is the color of the tanks on the second screen? I am using Stella to find the colors and change them with Hack-o-matic. I think the color should be 34 but I changed all of the 34s and I still get the brownish color. My kids want them to be green.

Here it is so far.

destroyhumantri.bin

Omegamatrix · March 16, 2009

The trick is the color registers ignore bit 0. #$35 is actually being loaded, but only #$34 is being stored in the color registers. This is useful for multiplexing your data. You can use odd number colors for enabling the vertical delay registers, or even for disabling them. Only bit 0 is used in them, so for example:

LDA #$35

STA COLUP0

STA VDELP0

This will enable the vertical delay, and still have the same color value as #$34 for player zero's color register. It saves 2 bytes over this:

LDA #$35

STA COLUP0

LDA #$01

STA VDELP0

In HOM3 you can find the color table from $06A1 to $06AD. I have no idea if the values are shared with anything else as I don't have time to disassemble the game. The above code didn't come from your hack, and is just meant as an example only