Strange Thing with Space Invaders

[khryssun]

While testing carts to define the SECAM palette, I've noticed a strange thing with my PAL cartrigde of Space Invaders.

 

I've put a screen capture here : http://www.khryssun.cjb.net/invaders.html

 

 

Each score is displayed with 2 colors.

But the Dark Green color used to display the score of the 2nd player doesn't match with the regular colors as they are defined in the STELLA manual(for SECAM system).

 

In fact, among the cartridges I've tested, it's the only one which uses thas color (the other ones are using the 8 regular colors palette) !

 

Refering to the Stella Manual, I've found this additional "Dark Green" color quite mysterious.

 

At first I've thought it was an interference problem due to the refresh rate/Capture interference of my capure video cart, so I've plugged my VCS into the TV to get a better display.

The TV picture was much more better and confirm this Dark Green color.

 

Then I've noticed a 1 pixel displace in the score numbers.

This seems to be the cause of the color alteration.

 

So, I 'am wondering if this color is a native color or the currupted original green color due to some tricky video operations.

 

anyway, the color display is perfect with no flicker effects.

 

I've check space invaders with emulators (Z26 and PCAE) then I've been surprised to discover that each score is display with 1 color only instead of 2.

 

Is the score displayed with a real VCS is monochrome with NTSC or PAL systems ?

- if yes, the emulation need to be improved.

- if no, are the colors used to display the scores are regular ones ?

[khryssun]

Step by Step....

 

Thanks a lot to Eckhard Stolberg for the info about the PAL system.

 

About the number of colors used to display each score player in Space Invaders (Using a REAL VCS - not emulators):

- 1 color in PAL

- 2 colors in SECAM (With a PAL Cart)

 

Anyone of you guys with a NTSC system may test Space Invaders and tell me the number of colors used to display each score player ?