Digigraphics
Encyclopedia
Digigraphics was one of the first graphical computer aided design systems to go on sale. Originally developed at Itek
on the PDP-1
as EDM (Electronic Drafting Machine), the efforts were purchased by Control Data Corporation
and ported to their machines, along with a new graphics terminal
to support it. Systems cost almost $500,000 and supported only a few users at a time, so in spite of a number of advantages it was not cost competitive with traditional manual methods and only a few systems were sold.
developed the first high-speed computer in the form of Whirlwind
, as part of the US Air Force's SAGE
project. SAGE not only required high-speed computers, but also graphical displays and light pen
s to operate them in real-time. The ideas developed during the SAGE program "leaked out" into the industry as SAGE wound down and its many members moved on to other projects. Ken Olsen
formed Digital Equipment Corporation
(DEC) and took many of the early SAGE programmers with them, Jack Gilmore and Charles Adams started Charles W. Adams Associates, one of the first programming companies, and Norm Taylor went to work at Itek
, who was attempting to build a computerized machine for retrieving photographs from a large library.
In 1959 Gilmore at Adams met with Taylor at Itek and proposed the idea of jointly developing a computer system for engineering design. Taylor convinced Itek's management to fund development, finally receiving the go-ahead in August 1960, retaining Adams Associates to write the software The natural choice for the host computer was DEC's newly-released PDP-1
. The PDP-1 had many of the same features as the earlier Lincoln Lab machines, including an optional vector display and light pen
support. The PDP-1 was based on an 18-bit word (1/2 the common mainframe 36-bits), had a 4,000-word core memory, and ran at about 0.1 MIPS.
Between mid-1960 and June 1961, the basic hardware was assembled, initially at Digital’s facility in Maynard, and later at Itek. Itek's PDP-1 was the second one to be delivered to a customer, the first being to MIT's Project MAC. A new 25 inch tube was used, larger than the PDP-1's standard 16 inch Type 30, but packaged in a similar hexagonal case. Input was via a combination of light pen for pointing, and the PDP-1's front panel switches for commands. An overlay was used on the front panel to indicate the special functions, and another on the display for labeling outputs.
Normally the PDP-1 display was driven in software, so as the complexity of the drawings increased, performance decreased. Itek addressed this problem by developing a "display processor" that would offload the task of refreshing the screen so the computer could be used solely for processing.Vector information was stored on the outer tracks of a 36 inch hard disk
supplied by Telex. Storing data only on the outside meant the linear speed was higher, providing faster throughput and allowing the system to generate 30 images a second from the data. Vectors were stored with 4-bit points to increase performance. In total, the disk system stored about 500,000 18-bit words, with about 20,000 bytes of vector data being used.
The US Air Force purchased one system for use at the Lincoln Labs on the PDP-1 that drove their Experimental Dynamic Processor, or DX-1. This version used a magnetic drum in place of the disk, its increased performance allowing more data to be stored before performance became an issue. This version used 6-bit words for locations instead of the prototype's 4-bit words, increasing resolution and allowing support for 2,000 inch documents instead of 800.
EDM was not the only CAD system being developed at the time. General Motors
started developing a similar system in 1959, and IBM
joined the effort in 1960. In spite of starting at about the same time, Digigraphics beat their DAC-1
to market by the better part of a year.
spy satellites. As a number of the company's acquisitions failed, Leghorn was removed from control of the company in May 1962 and replaced by Franklin Lindsay. Lindsay quickly shed off most of Leghorn's acquisitions, including EDM.
The system was quickly picked up by Control Data Corporation
(CDC), who were in the process of introducing a number of computer systems. Adams Associates won a contract to port the system to the CDC 3200 while CDC created a new version of the terminal, the CDC 274, controlled by the new CDC 1700 computer. Versions of the basic system were later ported to other CDC computers, including the 6000 family
, which could support several 274's on a single machine.
Over the next few years CDC sold a small number of the Digigraphics systems, first to aerospace companies including Lockheed
and Martin Marietta
, and later to the US Navy, who was interested in using them for submarine design. After several years, however, CDC decided the concept was unprofitable, and closed the division.
Itek
Itek Corporation was a US defense contractor that initially specialized in the field of camera systems for spy satellites. In the early 1960s they built a conglomerate in a fashion similar to LTV or Litton, during which time they developed the first CAD system and explored optical disk technology...
on the PDP-1
PDP-1
The PDP-1 was the first computer in Digital Equipment Corporation's PDP series and was first produced in 1960. It is famous for being the computer most important in the creation of hacker culture at MIT, BBN and elsewhere...
as EDM (Electronic Drafting Machine), the efforts were purchased by Control Data Corporation
Control Data Corporation
Control Data Corporation was a supercomputer firm. For most of the 1960s, it built the fastest computers in the world by far, only losing that crown in the 1970s after Seymour Cray left the company to found Cray Research, Inc....
and ported to their machines, along with a new graphics terminal
Computer terminal
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...
to support it. Systems cost almost $500,000 and supported only a few users at a time, so in spite of a number of advantages it was not cost competitive with traditional manual methods and only a few systems were sold.
Genesis at Itek
MIT's Lincoln LaboratoryLincoln Laboratory
MIT Lincoln Laboratory, located in Lexington, Massachusetts, is a United States Department of Defense research and development center chartered to apply advanced technology to problems of national security. Research and development activities focus on long-term technology development as well as...
developed the first high-speed computer in the form of Whirlwind
Whirlwind (computer)
The Whirlwind computer was developed at the Massachusetts Institute of Technology. It is the first computer that operated in real time, used video displays for output, and the first that was not simply an electronic replacement of older mechanical systems...
, as part of the US Air Force's SAGE
Semi Automatic Ground Environment
The Semi-Automatic Ground Environment was an automated control system for tracking and intercepting enemy bomber aircraft used by NORAD from the late 1950s into the 1980s...
project. SAGE not only required high-speed computers, but also graphical displays and light pen
Light pen
A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's CRT TV set or monitor. It allows the user to point to displayed objects, or draw on the screen, in a similar way to a touch screen but with greater positional accuracy...
s to operate them in real-time. The ideas developed during the SAGE program "leaked out" into the industry as SAGE wound down and its many members moved on to other projects. Ken Olsen
Ken Olsen
Kenneth Harry Olsen was an American engineer who co-founded Digital Equipment Corporation in 1957 with colleague Harlan Anderson.-Background:...
formed Digital Equipment Corporation
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
(DEC) and took many of the early SAGE programmers with them, Jack Gilmore and Charles Adams started Charles W. Adams Associates, one of the first programming companies, and Norm Taylor went to work at Itek
Itek
Itek Corporation was a US defense contractor that initially specialized in the field of camera systems for spy satellites. In the early 1960s they built a conglomerate in a fashion similar to LTV or Litton, during which time they developed the first CAD system and explored optical disk technology...
, who was attempting to build a computerized machine for retrieving photographs from a large library.
In 1959 Gilmore at Adams met with Taylor at Itek and proposed the idea of jointly developing a computer system for engineering design. Taylor convinced Itek's management to fund development, finally receiving the go-ahead in August 1960, retaining Adams Associates to write the software The natural choice for the host computer was DEC's newly-released PDP-1
PDP-1
The PDP-1 was the first computer in Digital Equipment Corporation's PDP series and was first produced in 1960. It is famous for being the computer most important in the creation of hacker culture at MIT, BBN and elsewhere...
. The PDP-1 had many of the same features as the earlier Lincoln Lab machines, including an optional vector display and light pen
Light pen
A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's CRT TV set or monitor. It allows the user to point to displayed objects, or draw on the screen, in a similar way to a touch screen but with greater positional accuracy...
support. The PDP-1 was based on an 18-bit word (1/2 the common mainframe 36-bits), had a 4,000-word core memory, and ran at about 0.1 MIPS.
Between mid-1960 and June 1961, the basic hardware was assembled, initially at Digital’s facility in Maynard, and later at Itek. Itek's PDP-1 was the second one to be delivered to a customer, the first being to MIT's Project MAC. A new 25 inch tube was used, larger than the PDP-1's standard 16 inch Type 30, but packaged in a similar hexagonal case. Input was via a combination of light pen for pointing, and the PDP-1's front panel switches for commands. An overlay was used on the front panel to indicate the special functions, and another on the display for labeling outputs.
Normally the PDP-1 display was driven in software, so as the complexity of the drawings increased, performance decreased. Itek addressed this problem by developing a "display processor" that would offload the task of refreshing the screen so the computer could be used solely for processing.Vector information was stored on the outer tracks of a 36 inch hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...
supplied by Telex. Storing data only on the outside meant the linear speed was higher, providing faster throughput and allowing the system to generate 30 images a second from the data. Vectors were stored with 4-bit points to increase performance. In total, the disk system stored about 500,000 18-bit words, with about 20,000 bytes of vector data being used.
On the market
The basic system was assembled and operational by early 1962, when Itek started actively marketing it as EDM. The system developed intense interest, and was even featured in a Time Magazine article:The operator's designs pass through the console into an inexpensive computer, which solves the problems and stores the answers in its memory banks in both digitalized form and on microfilm. By simply pressing buttons and sketching with the light pen, the engineer may enter into a running dialogue with an EDM, recall any of his earlier drawings to the screen in a millisecond and alter its lines and curves at will.
The US Air Force purchased one system for use at the Lincoln Labs on the PDP-1 that drove their Experimental Dynamic Processor, or DX-1. This version used a magnetic drum in place of the disk, its increased performance allowing more data to be stored before performance became an issue. This version used 6-bit words for locations instead of the prototype's 4-bit words, increasing resolution and allowing support for 2,000 inch documents instead of 800.
EDM was not the only CAD system being developed at the time. General Motors
General Motors
General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...
started developing a similar system in 1959, and IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
joined the effort in 1960. In spite of starting at about the same time, Digigraphics beat their DAC-1
DAC-1
DAC-1, for Design Augmented by Computer, was one of the earliest graphical computer aided design systems. Developed by General Motors, IBM was brought in as a partner in 1960 and the two developed the system and released it to production in 1963. It was publicly unveiled at the fall Joint Computer...
to market by the better part of a year.
Sale to Control Data
EDM was pitched to Itek while its president Richard Leghorn was in the midst of a buying spree. The company was publicly involved in the computer industry (its name was phonetically shortened from "information technology") but was in reality supplying only a single product, the cameras for the CIA's top secret CORONACorona (satellite)
The Corona program was a series of American strategic reconnaissance satellites produced and operated by the Central Intelligence Agency Directorate of Science & Technology with substantial assistance from the U.S. Air Force...
spy satellites. As a number of the company's acquisitions failed, Leghorn was removed from control of the company in May 1962 and replaced by Franklin Lindsay. Lindsay quickly shed off most of Leghorn's acquisitions, including EDM.
The system was quickly picked up by Control Data Corporation
Control Data Corporation
Control Data Corporation was a supercomputer firm. For most of the 1960s, it built the fastest computers in the world by far, only losing that crown in the 1970s after Seymour Cray left the company to found Cray Research, Inc....
(CDC), who were in the process of introducing a number of computer systems. Adams Associates won a contract to port the system to the CDC 3200 while CDC created a new version of the terminal, the CDC 274, controlled by the new CDC 1700 computer. Versions of the basic system were later ported to other CDC computers, including the 6000 family
CDC 6600
The CDC 6600 was a mainframe computer from Control Data Corporation, first delivered in 1964. It is generally considered to be the first successful supercomputer, outperforming its fastest predecessor, IBM 7030 Stretch, by about three times...
, which could support several 274's on a single machine.
Over the next few years CDC sold a small number of the Digigraphics systems, first to aerospace companies including Lockheed
Lockheed Corporation
The Lockheed Corporation was an American aerospace company. Lockheed was founded in 1912 and later merged with Martin Marietta to form Lockheed Martin in 1995.-Origins:...
and Martin Marietta
Martin Marietta
Martin Marietta Corporation was an American company founded in 1961 through the merger of The Martin Company and American-Marietta Corporation. The combined company became a leader in chemicals, aerospace, and electronics. In 1995, it merged with Lockheed Corporation to form Lockheed Martin. The...
, and later to the US Navy, who was interested in using them for submarine design. After several years, however, CDC decided the concept was unprofitable, and closed the division.