All models also has a 16-bit universal parallel port with separate input and output buses for connecting peripherals such as printers (Eastern Bloc printers used the incompatible ИРПР interface instead of the more popular Centronics port, so Centronics printers needed an adapter), mice or Covox DACs for sound output, and tape recorder port for data storage. Later models includes a manufacturer-supplied floppy drive controller (that can be plugged into a Q-Bus slot) by default. It was available for earlier models as an aftermarket part, but homebrew ones (that also often extends rather anemic 16K memory of original BK) are more popular. A cottage industry for such peripherals and mods flourished.