Der Computer als Werkzeug und Medium: Die geistigen und technischen Wurzeln des Personal Computers (review)

Der Computer als Werkzeug und Medium: Die geistigen und technischen Wurzeln des Personal Computers. By Michael Friedewald. Berlin: GNT Verlag, 1999. Pp. 497. DM 100.

Even though the impact of the personal computer on society has been extraordinary, there is no full-length history of the PC by a historian of technology. Michael Friedewald's Der Computer als Werkzeug und Medium seeks to close part of this gap in the history of computing by telling the story of the intellectual and technological roots of the PC.

Friedewald begins his story with a discussion of Vannevar Bush's futuristic information-storage machine, Memex, which could access vast amounts of data using microfilm technology. This is followed by a treatment of the Whirlwind and SAGE computer projects, which Friedewald calls precursors of the modern PC because of their interactive capabilities. Then comes a chapter devoted to J. C. R. Licklider's work at the Advanced Research Projects Agency on his vision of interactive computing-time sharing and human-computer interaction. And then comes Douglas Engelbart, who tried to find ways to use the computer for augmenting human intellect. Friedewald argues that the computer-based personal information-retrieval system developed by Engelbart at the Stanford Research Institute in the 1960s anticipated the way the PC is used today. Engelbart's ideas persisted in the Palo Alto Research Center (PARC) established by Xerox in 1969. Researchers at PARC attempted to develop the office of the future--the Xerox Alto computer, a graphical user interface (GUI), and the laser printer were among their projects--but Xerox failed in its attempt to market the Alto in the 1970s.

Last, Friedewald shows how new companies believing in the commercial success of inexpensive little computers based on the new microprocessor technology marketed the PC. This account of the pioneering phase of the PC is followed by a description of the rise of Apple Computer, the invention of the IBM PC, and the debut of the Apple Macintosh, which set a standard for GUI in 1984.

Friedewald paints a vivid picture of the history of personal computing. His book is well written, but uneven. The chapters on Engelbart and on PARC are the best, detailed and informative, and based on primary sources supplemented by interviews. Friedewald concentrates on biographical, institutional, and technical details rather than on analyzing Engelbart's concepts, which might have been more important to the general argument of the book. Most of the other chapters are based mainly on secondary literature. While these describe the historical characters and the machines in meticulous detail, they do have weaknesses.

Take the somewhat muddy description of analog computing on page 55. Friedewald argues that the analog computer was used to solve systems of equations, but it was not; rather, it is a device for solving differential equations. He also argues that the "analog device" Memex was not built because of the rapid eclipse of analog computers by digital computers, and yet analog computers were produced into the 1960s. Friedewald's argument makes one wonder whether it makes sense to compare an analog computer with the Memex in this way. To take a second example: in a section about pocket calculators (Taschenrechner), he argues that there was fierce competition until 1970, when in fact it was in 1970 that the first pocket calculators were put on the market by Japanese companies.

A major problem with Friedewald's study is his presentation of two different models of computer utility as a main connecting theme: the model of a mainframe computer as a giant calculator operated by a team of operators and programmers versus the model of an interactive, personal computer, with the Macintosh as the result. The invention of the PC marks only one branch in computer history, and judgments about the historical significance of various developments should not rest on whether they pointed toward...