williams-et-al-1983-apple-ii-computer-graphics

184 APPLE II COMPUTER GRAPHICSPLOT.To put something on the screen.POINT OF ORIGIN.begin.The point within a shape where the defining vectorsPOKE. A BASIC command which puts a specified value into a givenlocation.POSITION ADDRESS. The portion of the address for a byte on the Hi­Res screen which is given by that byte's position within its box. See theHi-Res memory map.PRE-CALCULATION. A method for reducing flicker. All the calculationsneeded for the animation are done before the figure begins to move. Theresults are stored in a table for reference.PRE-SHIFT. (1) The result of DRAWing the shape once, shifting theshape in any direction, and then XDRAWing over the original. (2) A wayof animating a shape by XDRAWing the necessary changes on top of it.PRIMARY PAGE.The first of two pages of either graphics or text.PROMPT CHARACTER. The character the Apple prints on your screen toremind you which language you are speaking to. Either APPLESOFT (]),Integer BASIC (>), or Monitor ( * ) .QUOTIENT.The result of a division.REMAINDER. The result of subtracting the product of the divisor and theinteger quotient from the number originally divided . Loosely (and muchmore understandably), what is left over after an integer division.RAM. An acronym for random access memory. RAM may be altered bythe program.ROM. An acronym for read only memory. ROM cannot be changed bysoftware-you cannot write to it, you may only read it.ROM RESIDENT.Something stored in ROM; therefore, it is p_ermanent.ROT. BASIC's Hi-Res shape rotation command. A shape rotates about itspoint of origin.ROUTINE.A program designed to accomplish a particular task.ROW ADDRESS. A portion of a graphics byte's address given by the rowwhich the byte's box occupies on the memory map.SCALE.A BASIC command used to enlarge shapes.SECONDARY PAG E.The second of two pages of either graphics or text.SECTOR. A bloc k of storage on a disk. One sector holds 256 bytes ofdata. DOS allows for 496 sectors to be available to the user.