Gameboy Radomising?

Archived from groups: rec.games.video.nintendo (More info?)

Here's one for ya... How come every time I play Tetris, I don't end up
playing the same game?

Since there is no clock in a gameboy like in a computer, and since the
original Tetris on the original gameboy didn't allow anything to be
saved on the game itself, what changing variable is the gameboy using
to generate the 'random' order of pieces?

This one's been bugging like crazy since it first occured to me. I'd
love to hear any explanations!

Archived from groups: rec.games.video.nintendo (More info?)

kk@thepopeshinesmyshoes.com wrote:
> Here's one for ya... How come every time I play Tetris, I don't end
up
> playing the same game?
>
> Since there is no clock in a gameboy like in a computer, and since
the
> original Tetris on the original gameboy didn't allow anything to be
> saved on the game itself, what changing variable is the gameboy using
> to generate the 'random' order of pieces?
>
> This one's been bugging like crazy since it first occured to me. I'd
> love to hear any explanations!

Simply put: even if there isn't a clock to get a random number from,
consider this:
>From the moment the gameboy is turned on, an internal random number
generator starts going (either in the hardware or software, it makes no
difference), and generates a new number every .01 seconds (this is just
for argument's sake)

Unless you (1) start the game the exact same number of hundreths of a
second after turning the gameboy on, and (2) you take exactly (to
within .005 seconds) the same time to play each piece (and that is a
cumulative .005 seconds, not .005 per piece), you will get a different
sequence.

There are other ways, but I think you should get the idea from my one
example.