other

IO

a stream should be thought of merely as a collection of data going to or coming from a piece of hardware, and
    - следует думать как просто колекция данных идущих к или от части устройсва
    In fact each stream really has two components,
        an input stream and
        an output stream.

a channel should be associated with a particular piece of hardware such as a printer.
    - должен быть сопоставлен с конкретный устройством такой как принтер
    Initially there are four channels -
        'K' - 'keyboard'
        'S' - 'screen'
        'R' - 'work space' - an internal channel used by the Spectrum to send data to the edit buffer.
        'P' - 'printer'