Backs up a game to the time specified. If totime is not specified the game is backed up by whatever GAMEINTERVAL is set at. Note that it is not possible to back up a game for a model that contains any of the pure delay functions DELAY FIXED, MATERIAL or INFORMATION.
Note that after executing a GAME>BACKUP it is probably best to force a reentry into the current screen so that any work in progress graphs will refresh themselves properly.
