Description APPLE COMPUTER, INC. An Apple® Lisa Computer An Apple® Lisa system unit marked model A6SB100, serial number B08B820360010, manufactured 82036, two 5.25in. 'Twiggy' floppy drives, 12" monochrome CRT display. With: mouse (marked model A9M0050, serial number 001268), and owner's guide (manual in grey and purple box). Without: original external keyboard 15.2in. (38.6cm.) x 18.7in. (47.5cm.) x 13.8in. (35.1cm) Specialist's Notes Apple's® Lisa, released in January, 1983 and based in part on Xerox's Alto, was developed in the early 1980s and was the first personal computer to sport a graphical user interface. While not a commercial success in part because of its high initial price ($10k in 1983), an underpowered processor (a 5 MHz 68000), and limited memory (512 KB), it set the foundation for Apple's later, very successful Macintosh line and inspired the design of Microsoft's Windows operating system. This particular unit has the early idiosyncratic 'Twiggy' floppy drives that could store over 800 KB but required special diskettes. This suggests it is a 1983 model (apparently manufactured in 1982) since in January 1984, Apple discontinued using these drives in the Lisa and replaced them with Sony 3.5" 'microfloppy' drives, which later became the industry standard.