Seeking info on AT&T Gemini-100 Electronic Blackboard

Summagraphics were founded in 1972 and 1978 released Bit Pad (sometimes considered to be the first commercial digitizer). Computer graphics research had been using 'exotic' input devices for years. A quick check of the CG literature gives a few biblography entrys the should help: [Dertouzos71] () Dertousoz, M.L. "Graphic Data Tablet", United States Patent 3,705,956, assigned to Computek, Incorporated, Cambridge, Massachusetts, December 12, 1972. Early electromagnetic digitizer tablet patent, using Gray Code grid pattern encoding, using phase of induced voltage Fernald73] () Fernald, Olaf H. "Optical graphic data tablet", United States Patent 3,761,877, September 25, 1973. Optical digitizing tablet: stylus shines a light on a transparent glass plate, with a scanner underneath [Hlady75] () Hlady, A.M. "Touch Sensitive Position Encoder using a Layered Sheet", United States Patent 3,916,099, October 28, 1975, assigned to Canadian Patent and Development Limited, Ottowa, Canada. Digitizer using surface acoustic wave [Kuipers75] () Kuipers, Jack United States Patent 3,868,565, February 25, 1975. Polhemus (?) patent on generating rotating fields to digitize position and angular position at same time (3-D tablet plus rotation, theta, phi, rho). (3,868,564 is a motor patent from the USSR) [Pobgee71] () Pobgee, P.J. and Parks, J.R. "Applications of a Low Cost Graphical Input Tablet", IFIP 1971, North-Holland, Amsterdam, pp ??, (TA-4-169) [Sutherland73] () Sutherland, I.E. "Three-dimensional Data Input by Tablet", Proceedings of the IEEE, Vol 62 No 4, April 1974, pp 453-461. [Uncapher71] (*) Uncapher, K.W. " The RAND Video Graphic System - An Approach to a General User-Computer Graphic Communication System ", RAND Corporation Research Report R-753-ARPA, April 1971 Copy on file has best image of RAND tablet and display hardware: shows photographic image and electronic text/ink displayed on same surface The RAND Video Graphics System is mentioned in RFC 113 dated 1971 and describes the use of a table to drive a video graphics display. HTH. Deano ----- Original Message ----- From: "John Honniball" <coredump(a)gifford.co.uk> To: <cctalk(a)classiccmp.org> Sent: Monday, July 07, 2003 8:03 PM Subject: Re: Seeking info on AT&T Gemini-100 Electronic Blackboard