A $15-million data-processing system called Finder has been delivered to the Air Force Strategic Air Command. Developed by Melpar, Falls Church, Va., under subcontract from Convair, Fort Worth, the system can correlate and analyze military data, prepare printer reports, charts and graphs, and display material in five colors on large tv screens. Finder occupies 7000 sq ft of floor space and contains a modified Burroughs 220 General-Purpose Computer (a vacuum-tube unit), and 89 Melpar-designed racks and consoles, which are completely transistorized.
Data to be processed are received on magnetic tape or punched cards. After code conversion, the data are transferred to a file of seven magnetic drums with a capacity of 31.5 million bits. A summary of data of immediate interest is automatically prepared on an auxiliary drum of 450,000-bit capacity. On command, this summarized data is displayed on a large-screen cathode-ray tube for operator analysis and decision.
New operational and deflection amplifiers had to be developed to implement the high presentation speeds and required accuracy of these displays. The deflection amplifier is capable of producing a 2400-V output with a rise time of less than 1 µsec and a settling time of 3.5 µsec. The operator selects and marks data with electrically generated cursors or a light brush. The electromechanical plotter has a plotting surface of 70 in. ×55 3/8 in. and plots a point anywhere on the surface with a maximum error of ±0.5 %. (Electronic Design, June 21, 1961, p. 34)
Note the mention of "electrically generated cursors and a light brush." Apparently, there was direct operator interaction with the display. The Burroughs 220 was one of the last vacuum-tube computers produced. For a full description of the B220, there's an excellent Web site devoted to the the history of Unisys Corp. computer systems: www.cc.gatech.edu/services/unisys-folklore/.