title: Analyzing and comparing the performance of two real-time playback systems.
abstract: A technique used in animated computer graphics involves the use of real-time playback.  This method is used when it is not possible to display frames of display code in real-time.  Instead, frames are compiled in advance at non realtime rates, saved in secondary storage, and played back at desired realtime speeds.  The basic design and operation of two such systems will be considered.  The more powerful of the two is built upon an Evans and Sutherland picture System I and utilizes animated vector graphics.  The other playback system is built upon a Terak micro computer display and represents an example of rudimentary raster graphics animation.  The synchronization, buffering, blocking and man-machine interfaces of both systems are detailed thus spotlighting their operational behavior.  A comparison of the two systems show:  that similarities in the logical organization of each system exist; that both systems are input bound; and both require their image files to be built on other computer systems.  The differences in the performance of the two systems can be attributed to technological differences between the two systems; the retrieval rates of their respective disk subsystems; and differences in the intent and purpose behind the design of each machine.  The systems are demonstrated by applying them to chemical modeling.  It is determined that playback is a useful technique for examining complicated sequential situations or for providing the concise and convenient representation of large amounts of data.
authors.affiliation: Naval Research Laboratory, Washington, DC 20375, USA.
authors.forename: J T
authors.initials: JT
authors.lastname: Egan
authors.forename: J
authors.initials: J
authors.lastname: Hart
authors.forename: R D
authors.initials: RD
authors.lastname: MacElroy
mesh_terms: D003196:Computer Graphics / Q000295:instrumentation*; D003198:Computer Simulation; D003199:Computer Systems; D003205:Computing Methodologies; D003626:Data Display; D008958:Models, Molecular; D014584:User-Computer Interface