Source : Free On-Line Dictionary of Computing

ZX Spectrum
     
         {Sinclair}'s first personal computer with a colour
        display.  The Spectrum used the {Zilog Z80} processor like its
        predecessors the {ZX-80} and {ZX-81}.  It was originally
        available in 16k and 48k versions using cassette tape and
        later grew to 128k and sprouted {floppy disks}.  It had a
        wider and more solid case and a marginally better "dead flesh"
        keyboard.  Unlike the earlier models, it didn't require the
        presence of a cold carton of milk to prevent it overheating.
        It was possibly the most popular home computer in the UK for
        many years.
     
        The {TK-90X} was a clone.
     
        (1995-11-04)