Dec 31, 1970
A user's guide to VPACK, a set of subroutines enabling Fortran programs to communicate with the Video Graphic System (R-753). VPACK builds and transmits pictures, receives RAND Tablet and keyboard input, and, if desired, produces hardcopy of displayed images. VPACK routines perform relatively primitive functions, e.g., drawing lines or positioning characters. Calls to several VPACK routines can be combined for more complex functions. The VPACK display routines operate on a buffer of size and address specified during initialization. Thereafter, VPACK maintains and updates the space in use and the storage position of the display commands. If the buffer space occupied exceeds the maximum VGS allows for one picture, VPACK automatically segments the picture at appropriate points. Although written for VGS, VPACK comprises a relatively small package of code that can be replaced for use on other graphics hardware, without any change in the application program. This version was developed for BIOMOD (R-617).