Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84 / ST 1.0; site saber.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!ihnp4!nsc!saber!skinner From: skinner@saber.UUCP (Robert Skinner) Newsgroups: net.graphics Subject: XOR cursors Message-ID: <1858@saber.UUCP> Date: Fri, 8-Nov-85 14:37:57 EST Article-I.D.: saber.1858 Posted: Fri Nov 8 14:37:57 1985 Date-Received: Sun, 10-Nov-85 08:34:31 EST Distribution: net Organization: Saber Technology, San Jose, CA Lines: 56 *** REPLACE THIS LINE WITH YOUR MESSAGE *** A while back a discussion was started about someone who owned the patent to doing non-destructive cursors by XOR'ing. A friend of mine discussed this not long ago with the owner of the patent, because my friend was infringing on parts of the patent. By the way, this company is not asking just $100, but $10K-25K, depending on the extent of the infringement. The company is CADTRAK of Sunnyvale, CA. They made a workstation aimed at chemical plant design, but have since scrapped that, in favor of porting the software to PCs using TECMAR graphic boards (which probably infringe on the same patent). Supposedly the president was seen at Siggraph, talking to various vendors. Asking how their hardware did this or that. Depending on the answer, he would give them the info on this patent, and hit them up later for money. Here is a brief list of the items covered under patent #4197590, granted in 1980, and an addendum #31200, granted in 1983. The descriptions given to me was terse, I'll expand a little on some that may not be obvious. * Use of hardware to XOR cursors non-destructively * Hardware for generation of the shape and location of a cursor. * Hardware image zoom by pixel replication * Pixel replication zoom by a scale factor * Hardware for smooth panning (for apparent animation) * Hardware grid patterns mixed with the video * A method of modulating the video (after color table lookup) for generation of matte backgrounds (this I didn't fully understand) * Double Buffering image memory * The simultaneous display of two separate image buffers on one video display. * Read skip control: selectively skipping the readout of portions of image memory. From what I think I know about the CADTRAK workstation, my personal opinion is that it did a lot of unique and innovative things, e.g. simultaneously displaying two parts of the image buffer and panning each independently. It seems as though while they were patenting the innovative features, they went for the works. I'm almost more disappointed in the patent office for granting this (in 1980 even!) than with CADTRAC for taking advantage of it. Any other comments I'll reserve for those on the net. ------------------------------------------------------------------------------ The difference between America and England is, the English think 100 miles is long distance and Americans think 100 years is a long time. Name: Robert Skinner Snail: Saber Technology, 2381 Bering Drive, San Jose, California 95131 AT&T: (408) 945-0518, or 945-9600 (mesg. only) UUCP: ...ihnp4!saber!skinner