Do Videogames/Gaming Systems use Special COMPRESSION techniques ?
 

i've always been amazed at just how relatively small in size videogames are. From classic arcade games which are like 20k ! to games on the PS1/DC etc which fit on 1 cd but which fit a godaweful amount of stuff on that 1cd

what's the secret ?

It's not so much that video game code is small so much as Windows code is immensely bloated.

I'm not sure if they are compressed as uncompressing on the fly might be too processor intensive. I do know that in some games the music is compressed in .xa format for PS1 games like symphony of the night (which practically sounds CD quality).

I think I remember a few games using mp3 compression (I believe Top Gear Overdrive (not so good a game though) on the N64 used mp3 to include songs and even mentioned it on the title screen. And of course, Factor 5 does wonders using compression by making high quality sound take up less memory while the decompression hardly uses any processor cycles.

I don't know if that answers your question though....the secret is really good and efficient programming techniques. There's more than one way to code something, and always a more efficient way to optimize code.
With games now on DVD formats, there isn't really much need for compression, the only one they use now is Mpeg2 I believe for the video.