Terrahawks Noughts and Crosses

Or Tic-Tac-Toe if you prefer

Yes, this is a blog about a very old TV show.

I went down a rabbit hole. A very stupid rabbit hole. A meaningless rabbit hole.

There was a 1983 Gerry Anderson puppet show “Terrahawks”.

It wasn’t as good as his older stuff (e.g. the original Thunderbirds). Maybe I was also that little bit older when I first watched it (I would have been around 15 when it started).

Earth was under attack by an alien, Zelda. Earth’s defenders has robotic spheres (“Zeroids”). Zelda had cubes.

At the end of each episode there was a game of noughts and crosses, with the zeroids playing the “O” and the cubes playing the “X” (‘cos they had an X mark on top of them).

game animation

Since I recently got the box set (it was cheap) I had to analyse the games. Joshua (Wargames) would wipe the floor with both teams, but let’s see.

There were 39 episodes. Each game started with the Zeroids (O) going first.

This make it easy to create a notation for recording the games; just number the squares and record the order they’re filled in. The first square is always an “o” and then they alternate “x” and “o”.

So the number 3975142 would result in this game. Yay zeroids win!

1 2 3 4 5 6 7
  o
   
   
  o
   
  x
  o
   
o x
  o
 x 
o x
o o
 x 
o x
o o
xx 
o x
ooo
xx 
o x

Now to complicate things, the cubes cheat. they might move at the end and knock the zeroids out of place to claim a win. eg “2158647 8-7” Indeed, the only way the cubes won was by cheating like this.

1 2 3 4 5 6 7 8
 o 
   
   
xo 
   
   
xo 
 o 
   
xo 
 o 
 x 
xo 
 oo
 x 
xo 
xoo
 x 
xo 
xoo
ox 
xo 
xoo
x  

You can see an example video of this in action; this is from the first episode.

What I learned

It turns out there were only 13 different games. Episodes would repeat. I guess the animation was too expensive for 39 games.

Except there’s only 38 games, ‘cos one episode (“A Christmas Miracle”) didn’t end in a game, but with Sergeant Major Zero on his perch dressed as Santa.

Not every game was repeated evenly, either. The game in the first episode never got repeated; other games maybe 3 or 4 times.

All in all the score was 19:19.

As a kid I kinda hoped the winner represented who came out on top in the episode, but there really doesn’t seem to be any correlation between the game winner and the episode.

Which makes sense, since the Terrahawks were normally on the defensive.

What I missed

Now I had vaguely wondered about symmetry. Noughts and Crosses boards have rotational and reflectional symmetry. What I’d missed was that the character animations only had reflectional symmetry in the Y axis. So I could have sat down and worked this out, rather than being lazy.

When I posted my early learnings to twitter I was lucky enough for the actual artist to pick up on this and reply. How cool is that!

He confirmed that there were only 7 games animated; 6 were reflections and the first episode was the only one with a unique game. He even has a youtube video on this.

The games

Oh, if people care, these are the episodes for each game.

1459238

  • 1.05 The Ugliest Monster Of All
  • 2.06 My Kingdom For A ZEAF
  • 3.04 Space Cyclops
1 2 3 4 5 6 7
o  
   
   
o  
x  
   
o  
xo 
   
o  
xo 
  x
oo 
xo 
  x
oox
xo 
  x
oox
xo 
 ox

1523746 6-9 3-6

  • 1.01 Expect The Unexpected
1 2 3 4 5 6 7 8
   
 o 
   
 x 
 o 
   
 xo
 o 
   
 xo
 o 
x  
 xo
oo 
x  
 xo
oox
x  
 xo
oox
x  
 x
ooo
x x

1795362

  • 1.09 Thunder Path
  • 2.04 The Ultimate Menace
  • 2.11 Cry UFO
1 2 3 4 5 6 7
o  
   
   
o  
   
x  
o  
   
x o
o  
 x 
x o
o o
 x 
x o
o o
 xx
x o
ooo
 xx
x o

2158647 8-7

  • 2.08 Cold Finger
  • 2.13 Ma’s Monsters
  • 3.12 The Sporilla
1 2 3 4 5 6 7 8
 o 
   
   
xo 
   
   
xo 
 o 
   
xo 
 o 
 x 
xo 
 oo
 x 
xo 
xoo
 x 
xo 
xoo
ox 
xo 
xoo
x  

2358469 8-9

  • 1.11 Mind Monster
  • 3.06 Child’s Play
  • 3.13 Gold
1 2 3 4 5 6 7 8
 o 
   
   
 ox
   
   
 ox
 o 
   
 ox
 o 
 x 
 ox
oo 
 x 
 ox
oox
 x 
 ox
oox
 xo
 ox
oox
  x

3657218

  • 1.03 Thunder-Roar
  • 2.01 Operation SAS
  • 3.07 Jolly Roger One
1 2 3 4 5 6 7
  o
   
   
  o
  x
   
  o
 ox
   
  o
 ox
x  
 oo
 ox
x  
xoo
 ox
x  
xoo
 ox
xo 

3975142

  • 1.10 From Here To Infinity
  • 3.02 First Strike
1 2 3 4 5 6 7
  o
   
   
  o
   
  x
  o
   
o x
  o
 x 
o x
o o
 x 
o x
o o
xx 
o x
ooo
xx 
o x

4517328 2-3

  • 1.04 Happy Madeday
  • 2.09 Unseen Menace
  • 3.08 Runaway
1 2 3 4 5 6 7 8
   
o  
   
   
ox 
   
o  
ox 
   
o  
ox 
x  
o o
ox 
x  
oxo
ox 
x  
oxo
ox 
xo 
o x
ox 
xo 

5873149

  • 2.02 Ten Top Pop
  • 3.01 Two For The Price Of One
  • 3.09 Space Samurai
  • 3.11 Operation Zero
1 2 3 4 5 6 7
   
 o 
   
   
 o 
 x 
   
 o 
ox 
  x
 o 
ox 
o x
 o 
ox 
o x
xo 
ox 
o x
xo 
oxo

5891367

  • 1.02 Expect The Unexpected Part 2
  • 1.13 To Catch A Tiger
  • 2.05 Midnight Blue
  • 3.05 Doppelganger
1 2 3 4 5 6 7
   
 o 
   
   
 o 
 x 
   
 o 
 xo
x  
 o 
 xo
x o
 o 
 xo
x o
 ox
 xo
x o
 ox
oxo

6539128 2-1

  • 1.07 The Gun
  • 2.03 Play It Again SRAM
  • 3.10 Timewarp
1 2 3 4 5 6 7 8
   
  o
   
   
 xo
   
  o
 xo
   
  o
 xo
  x
o o
 xo
  x
oxo
 xo
  x
oxo
 xo
 ox
x o
 xo
 ox

7453289 2-1 3-2 5-6 4-5

  • 1.08 Gunfight At Oakys Corral
  • 2.07 Zero’s Finest Hour
  • 2.10 Space Giant
1 2 3 4 5 6 7 8
   
   
o  
   
x  
o  
   
xo 
o  
  x
xo 
o  
 ox
xo 
o  
 ox
xo 
ox 
 ox
xo 
oxo
ox
xo
oxo

9651287 2-3 1-2 5-4 6-5

  • 1.06 Close Call
  • 2.12 The Midas Touch
  • 3.03 Terratomb
1 2 3 4 5 6 7 8
   
   
  o
   
  x
  o
   
 ox
  o
x  
 ox
  o
xo 
 ox
  o
xo 
 ox
 xo
xo 
 ox
oxo
xo
ox
oxo

No game! Picture of Zero dressed as Santa!

  • 1.12 A Christmas Miracle

Summary

You can see each game is 7 moves long, and if no one (well, the zeroids) has won after 7 moves then the cubes cheat.

It’s also very clear to see the symmetry in the last 2 (“7453289 2-1 3-2 5-6 4-5” and “9651287 2-3 1-2 5-4 6-5”).

The show wasn’t as good as I remembered, but the music and how it sync’d to the end-game was clever and fun.

Apparently the American broadcast never got this. How unfortunate…

And now I have the end credit theme tune stuck in my head.

Oh, and if you want the source that generates the really bad HTML that draws the game boards, it’s here.