Synchronizing Graphics Data Streams to Alphanumeric Data Streams in Display Products
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
This article describes, in a controller-display terminal system, a subsystem for synchronizing graphics and alphanumeric (A/N) data output from respective data buffers to the cathode ray tube (CRT) display, and for interleaving that data transfer with other operations such as read/write between the refresh memories which store that data and the controller. In particular, the subsystem includes means for providing an enhanced I/O data refresh of the buffered graphics data during retrace of the CRT display beam. Fig. 1 shows a general block diagram of a graphics-A/N display system embodying the invention. The data bus 10 provides eight-bit bytes to an A/N Text Buffer 12 where they are stored as character points corresponding to the character display positions on the screen.