Xerox Alto
The Xerox Alto was developed in 1973 at Xerox PARC research center and was the first computer with a graphical user interface ( GUI).
The first sketches were made in 1972 under the developer Butler Lampson. The first machines by Clement Design Labs in collaboration with Doug Fairbairn ( Xerox PARC ) were prepared. Other participating developers were Edward M. McCreight, and Charles P. Thacker, Bob Metcalfe and Dave Boggs. The CPU consisted of a bit-slice processor which was based on the 74181 chip from Texas Instruments and was operated at a clock rate of 5.8 MHz. The 16 - bit shift register and the entire I / O were controlled by microcode and were connected to the main memory and the ALU via a parallel 16- bit data bus. The main memory was 128 KB in size and could be expanded to 256 kB.
The removable hard disk ( Diablo Systems, a company that was later acquired by Xerox ) took 2.5 MB. Since these drives ( Diablo Model 31 and 44) were front-end loader, the system could be expanded to a second disk drive. The housing of the computer was the size of a small chest freezer in about. The computer was often referred to by its progressive approach as the first personal computer or workstation as the first, although its technical structure corresponded to a minicomputer. The findings of the first years took on the basis of the first version I Alto to numerous improvements of the hardware and software, allowing both the computing power and usability were more efficient, and in 1976 finally could be implemented at the Alto II.
The default configuration consisted of a monochrome monitor with a resolution of 606 × 808 pixels and an uncoded 61-key keyboard. He already had a three-button mouse, used raster graphics, windows, menus and icons. About the Ethernet protocol he could with other computers at a transmission rate of 3 Mbit / s are connected, which also e-mail could be used by the connected Intranet addition to data exchange. In addition, the connection of a Diablo HyType - Typenraddruckers and a five - finger chord keyboard was possible.
The computer was used mainly in research and development. Due to the enormous success of the Alto about 2000 pieces were made in a period of ten years. The price was in 1973 at about $ 32,000 ( according to current purchasing power about 117,000 Euros ). Many of the innovations in the Alto were later taken over by Steve Jobs for the Apple Macintosh.
The special feature of the WYSIWYG interface used is that the monitor could be a U.S. letter sheet 1:1 in portrait mode. Based on an improved hardware of the Alto, a Lisp machine named Dolphin was developed at PARC. Alto was also known by the object-oriented programming language Smalltalk -80, which was developed together with the high level language Mesa and their successors Cedar it.
From 1980 to 1981 Xerox Alto computer at Xerox were used System Development Department for the development of the successor Xerox Star, in which the first commercial use of a GUI was.