资料来源 : Free On-Line Dictionary of Computing

VIC-20
     
         A home computer made by {Commodore} with a {6502}
        {CPU}, similar in style to the {Commodore 64} and {Commodore
        C16}.  The VIC-20 was released before the C64, and after the
        {Commodore PET}(?).  It was intended to be more of a low-end
        home computer than the PET.
     
        The VIC-20 had connectors for game cartridges and a {tape
        drive} (compatible with a C64).  It came with five {kilobytes}
        of {RAM}, but 1.5 KB were used by the system for various
        things, like the video display (which had an unusual 22x20
        char/line screen layout), and other dynamic aspects of the
        {operating system} (such as it was).  The RAM was expandable
        with a plug-in cartridge which used the same expansion port as
        games.  Port expander boxes were available to allow more than
        one cartridge to be connected at a time.
     
        RAM cartridges were available in several sizes: 3K, 8K, 16K
        and 32K.  The internal memory map was re-organised with the
        addition of each size cartridge, leading to the situation that
        some programs would only work if the right amount of memory
        was available.  The 32K cartridges were all third-party and
        had switches to allow the RAM to be enabled in sections so
        that any expansion size could be achieved.
     
        {BASIC} programs could use at most 24 KB of RAM.  Any extra
        occupied the location usually used by ROM cartridges
        (i.e. games).  This allowed people to copy ROM cartridges to
        tape and distribute them to their friends, who could load the
        tape into the top 8k of their 32k RAM packs.
     
        The name "VIC" came from the Video Interface Chip that was
        also used in the other, later, Commodore 8-bit computers.
     
        (2000-03-28)