Charles P. Thacker

The late Charles P. “Chuck” Thacker was named recipient of the ACM - IEEE CS Eckert-Mauchly Award for fundamental networking and distributed computing contributions including Ethernet, the Xerox Alto, and development of the first tablet computers. Often hailed as an “engineer’s engineer,” Thacker made fundamental contributions across the full breadth of computer development, from analog circuit and power supply design to logic design, processor and network architecture, system software, languages, and applications.

In 1970, Xerox opened its Palo Alto Research Center (PARC) and hired several leading computer scientists and engineers, including Thacker. Early on, the staff at Xerox PARC was using a time-sharing approach in which various terminals were connected to a single computer. Because time sharing was a slow and cumbersome process, leaders at Xerox PARC conceived the idea of developing personal computers as part of a network that would be used for communication as well as computation.

Mainframe computers in the early 1970s were so large that they took up whole rooms, and their expense made them relatively scarce. Under the paradigm at the time, computer architecture needed to be either scaled up (more hardware) for better performance, or scaled down (less hardware) for lower cost. Thacker realized that a personal computer would need to be designed differently from a standard computer to address space constraints, maintain strong performance, and be inexpensive if it was to become pervasive.

At the same time, the idea of a “personal” computer that would be geared more toward human-paced activities called for the engineers to prioritize input/output (I/O) functions rather than application functions, as had traditionally been the case.

The new design feature Thacker employed as the Lead Engineer in what would become the Xerox Alto Computer was a central processing unit (CPU) microprocessor that used microcode for most of the computer’s I/O functions, rather than hardware. The microcode controlled various tasks, including executing the normal instruction set, memory refresh, and network and display functions. The Xerox Alto was therefore not simply a mini-version of existing computers, but had a novel architecture that allowed it to deploy new kinds of software.

Today the Alto is recognized as being the first modern personal computer. The initial architecture of the Alto gave rise to other important inventions developed by engineers at Xerox PARC including WYSIWIG (What You See Is What You Get) editing, laser printing, drawing and painting, email, mouse-driven graphical user interfaces, and many other features that are commonplace in personal computers today.

Another critical innovation of Thacker’s that was an outgrowth of his work on the Alto was the development of hardware for Bob Metcalfe’s invention of the Ethernet Local Area Network (LAN), which facilitated communication among computers.

Twenty years after the development of the Xerox Alto, Thacker made another foundational contribution to personal computing with the development of the Lectrice, a laboratory prototype for today’s portable PCs. He went on to develop a prototype upon which Microsoft Tablet PC software was developed, as well as a system for reading electronic books that laid the groundwork for many of today’s e-readers. One of Thacker’s most recent contributions is the design of AN3, a low-cost, efficient circuit-switched data center network.

The ACM - IEEE CS Eckert-Mauchly Award is known as the computer architecture community’s most prestigious award. ACM and IEEE Computer Society co-sponsor the award, which was initiated in 1979. It recognizes contributions to computer and digital systems architecture and comes with a $5,000 prize. The award was named for John Presper Eckert and John William Mauchly, who collaborated on the design and construction of the Electronic Numerical Integrator and Computer (ENIAC), the pioneering large-scale electronic computing machine, which was completed in 1947.