Flip

Used to flip upper and lower cases inside programsOn the earliest models of the PET, the default display uses the "graphics" character set. If you type any letter, you get an uppercase letter, and if you press SHIFT while typing a letter, you get a PETSCII graphics character. For example, the S key gives you an uppercase 'S', while SHIFT+S gives you a PETSCII heart symbol. There are no lowercase letters available in the graphics mode.

If you want to do something where you need lowercase letters (like word processing), POKE 59468,14 switches the PET to its "business" character set, with both upper- and lowercase letters available for typing. This character set switching comes with an odd quirk: the lowercase letters replace the shifted PETSCII graphics characters, which means that typing that S still gives you an uppercase 'S', but SHIFT+S now gives you a lowercase 's', which is the opposite of what you'd expect.