My blog - LouiseSchmidt

When you pause a game - you are simply calling a routine inside the running code to suspend the frame draw and other components. The game is still running - it just appears to be "waiting" on you. As such, it's in a volatile state. If you kill the power - the game goes with it. Think of this less of pausing and more of suspension of state. When you suspend the game, you aren't just telling the game to put itself into a wait state - you are actively saving the contents (in this case, the volatile memory) into a structure that can be returned to later. In most cases, this is a file. So, rather than having the game still running as some form of background task (still susceptible to power outage, etc) you are saving the entire state of memory and committing it to a file. Once committed, the machine is free to continue on and do other things. When you wish to return to the state, the contents of the file are loaded back into memory and rather than executing at the beginning, execute where you left off. It's no different than say suspending Windows - it just creates a dump of the active memory into a file (hiberfile) and sets a flag. When the machine is booted, the boot sequence notices there is a flag saying "dude, we need to pick up where we left off..." and instead of starting the entire boot sequence from scratch, it re-loads the guts of that file structure back into memory and executes from there. Back in the day I had one of those grey market "backup" devices for my SNES. All it was doing there was doing mem dumps of the game state, which allowed me to pause at any point ever. Pretty kickass for what it was back then...