RFC 549 (rfc549) - Page 2 of 12
Minutes of Network Graphics Group meeting, 15-17 July 1973
Alternative Format: Original Text Document
RFC 549 Minutes of Network Graphics 15-17 July 1973 and aircraft position and velocity. These descriptions are highly encoded--they are not pictures in any general sense. The rate at which the simulation proceeded was adequate. Jim Michener described the results of an experiment in which the E&S LDS-1 at MIT-DMCG was used to generate stylus inking input for a character recognition program at SDC. The experiment was plagued with difficulties including bugs in SDC's NCP and scheduling of experimental/debugging sessions. When the experiment was finally terminated (due to planned extensive hardware modifications at DMCG) a clear understanding had not yet emerged, but apparently network transmission delays had been experienced of up to 20 seconds. Dan Cohen described an Aircraft Flight Simulator which interacts with a user at the Harvard PDP-1. The simulation takes place on a PDP-10. Network traffic is approximately 200 bits from the PDP-1 to the PDP-10 and several thousand bits in the opposite direction. It has been found that at least 5 updates are required per second to give the "pilot" an adequate feeling of control. The Harvard PDP-10 and one at BBN have been used, the latter at 6 AM to avoid loading problems. John Pickens described UCSB's status regarding output in level 0 Network Graphics Protocol (NGP-0). Steve Bunch reported that he has an Imlac monitor which accepts NGP-0 directly. Programs have been developed at CCN (using subroutine packages modeled after plotter packages) which build files containing pictures in NGP-0. Other programs output the pictures either to a Gould plotter or a storage display (in device specific code) or to an Imlac (in NGP-0 form). Steve Holmgren briefly described a Fancy Arpa Network Graphics System (FANGS) under development at UCSD. Discussion of Modifications in the Graphics Protocol David Egli reported that he and Jim Foley (of Univ. of North Carolina) thought that the graphics protocol should have the ability to replace items, and that 3 dimensional data should be allowable. Jim Foley also thinks that a subpicture call should be able to specify a rate of rotation, scaling, and translation, in addition to initial values for these. An extended coffee break followed to allow perusal of the documents distributed.
