White Pointer Gaming is another excellent source of retro game hardware information, and a few days ago they uploaded a dive into the specifics of the real time clock used in Pokemon Generation 2 (14 minutes), and as an encore discussed Gameboy mapper chips, a related topic. It seems the clock hardware is on quite a few other GB games as well, as it’s built in to a common mapper chip, but it needs extra power to run the clock, and an oscillator to keep the time accurate. Another game that uses the same mapper, but doesn’t have the oscillator? Pokemon Generation One. Hmmm!
The video mentions that powering the clock and oscillator causes Pokemon Gold, Silver and Crystal cartridges to run out of battery power, and lose their saved game data, much faster than other Gameboy carts with save game battery. Sorry to break it to you; your Pokemon are probably gone by now. Poor out a health potion for Pikachu.
Another interesting fact revealed is, the clock works by recording raw time since the game was last powered on, and the actual date and time are fully updated when the game is started up. If you wait a long time between plays, over 511 days, the timer can wrap around and lose track of how long it’s been.
