The Jargon File (version 4.4.7, 29 Dec 2003):

video toaster
 n.

    Historically, an Amiga fitted with a particular line of special video
    effects hardware from NewTek ? long a popular platform at special-effects
    and video production houses. More generally, any computer system designed
    specifically for video production and manipulation. Compare web toaster
    and see toaster.