total aside, but i was reminded of one of the cooler things i learned about the gameboy: people actually use binary coded decimal, for things like scores, lives, or time
to display text on a gameboy, you need to create a set of tiles for each letter or number. to show the number "123" you have to tell the gameboy to use a "1", "2" and "3" tile
which means that when you store a number in binary coded decimal, it's already in the perfect form to pass onto the tile mapper
i used to think BCD was a relic of the past, but it turns out the overhead of converting from binary to decimal adds up when you're frequently displaying numbers as text
for example: i believe one of the large tech corps found out that their timestamp routine was taking up huge chunks of cpu time, as it was called heavily for logging
by storing the time as binary coded decimal from the outset, printing the time becomes almost a free operation