A method of encoding graphical data to be displayed by an output terminal where the output terminal has plural modes of operation and procedures are undertaken to select, using past history and future anticipated operation, the fastest and most efficient mode of operation. In the faster modes, part of the information defining the location to be reached and the symbol to be displayed are stored and remembered. In these modes less information need be transmitted to the terminal to execute a move and successive moves are thereby executed faster. The optimum mode may be selected by examining previous location information to predict a possible mode change.
A technique for processing pictorial information to enable its display on a desired display device independent of the latter's resolution characteristics includes a unique encoding procedure and a corresponding decoding and display procedure. Attributes of each element of a picture or image (such as its color) are specified by a group of N bits. The bits are assembled to form M-bit active portions of a series of bytes. M and N need not be integrally related. Ones of the words also define the size of the elements with respect to a unit display space (the horizontal and vertical dimensions of each element can be different), the order in which the elements are arranged in the picture (e.g., left to right or vice versa) and the value of N. The bytes are decoded and the picture displayed by locating each pel in the unit screen coordinate space, mapping each location to a corresponding storage location in an array formed by a frame memory, writing the attributes of each pel in one or more of the storage locations, and sequentially reading the contents of the memory and applying the output to the display device.
