ZOG was an early

hypertext Hypertext is E-text, text displayed on a computer display or other electronic devices with references (hyperlinks) to other text that the reader can immediately access. Hypertext documents are interconnected by hyperlinks, which are typi ...

system developed at

Carnegie Mellon University Carnegie Mellon University (CMU) is a private research university in Pittsburgh, Pennsylvania. One of its predecessors was established in 1900 by Andrew Carnegie as the Carnegie Technical Schools; it became the Carnegie Institute of Technology ...

during the 1970s by Donald McCracken and Robert Akscyn. ZOG was first developed by

Allen Newell Allen Newell (March 19, 1927 – July 19, 1992) was a researcher in computer science and cognitive psychology at the RAND Corporation and at Carnegie Mellon University’s School of Computer Science, Tepper School of Business, and Department ...

and

George G. Robertson George G. Robertson is an American information visualization expert and senior researcher, Visualization and Interaction (VIBE) Research Group, Microsoft Research. With Stuart K. Card, Jock D. Mackinlay and others he invented a number of Informatio ...

to serve as the front end for AI and Cognitive Science programs brought together at CMU for a summer workshop. The ZOG project was as an outgrowth of long-term artificial intelligence research led by Allen Newell and funded by the

Office of Naval Research The Office of Naval Research (ONR) is an organization within the United States Department of the Navy responsible for the science and technology programs of the U.S. Navy and Marine Corps. Established by Congress in 1946, its mission is to plan ...

. A second version of ZOG was installed as the key interface between users and logistics on the Nimitz class carrier USS ''Carl Vinson'' in 1983.

Composition

ZOG consisted of "frames" that contained a title, a description, a line containing ZOG system commands, and selections (menu items) that led to other frames. ZOG pioneered the "frame" or "card" model of hypertext later popularized by HyperCard. In such systems, the frames or cards cannot scroll to show content that is part of the same document but held offscreen. Instead, text that exceeds the capacity of one screen ''must'' be placed in another (which then constitutes a separate frame or card) The ZOG database became fully functional around 1977. Beginning in 1980, ZOG was ported from DEC VAX version (written in an experimental language called "L*") to the Pascal-based

Three Rivers PERQ The PERQ, also referred to as the Three Rivers PERQ or ICL PERQ, was a pioneering workstation computer produced in the late 1970s through the early 1980s. In June 1979, the company took its very first order from the UK's Rutherford Appleton La ...

workstation and was used for a shipwide local area network on the American

aircraft carrier An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...

'' USS Carl Vinson''. In 1981, Rob Akscyn and Donald McCracken, two principals from the ZOG project, founded Knowledge Systems to develop and market a commercial follow-on to ZOG called KMS ("Knowledge Management System")..

Syntax

An example of syntax from one dialect of ZOG:

This TITLE line summarizes the frame's contents

This TEXT expands the frame's main point of information, but is sometimes omitted.
The OPTIONS below are used to point to subordinate sections or to provide an
enumerated expansion of the main topic. LOCAL PADS do not have the connotation of
leading to deeper detail, but rather to tangential points such as related material
in another document or database. Invoking programs is another function typically
reserved for LOCAL PADS. At the bottom of the frame is a set of general functions
called GLOBAL PADS, which are available in every frame.

1. This OPTION leads to another frame
2. Options are often used like subpoints in an outline
3. -This option leads nowhere (indicated by the minus sign at the front)

References

{{reflist Hypertext 1970s in the United States 1970s software Carnegie Mellon University software