Abstract: A television-connected microprocessor system designed for use primarily as a television game or education system. The system is designed to accept source programming from cartridges that are interchangeable. The cartridges utilize either a ROM or a RAM to store the source programming. The source program is stored in the cartridge ROM or RAM in a higher level language, such as BASIC and interpreted for use by the microprocessor. Each ROM cartridge comes with a keyboard entry device as an integral part thereof which is uniquely adapted to the programming in the cartridge and the games or training sequence dictated thereby. By using a RAM cartridge, the user may enter his own source program by way of a general purpose keyboard or a tape recorder. Keyboard overlays are utilized to adapt the general purpose keyboard to the particular game or training sequence dictated by the source program entered into the cartridge RAM by the user.

Abstract: A color pattern and alphanumeric character generator for use with raster-scanned CRT display devices wherein the color background patterns and the characters are generated in an integrated manner. As a result, the apparatus utilized is considerably simplified and the color pattern display obtainable is more complex and more easily varied than hitherto was possible in an apparatus of this type. The viewing area of the raster-scan CRT is divided into a matrix of character cells. Each character cell is in turn divided into a plurality of color cells, each color cell being a matrix of dot positions on the display area of the CRT. The relationship of the number of color cells in each character cell and the number of dot positions in each color cell is an even integer. A display RAM, addressed by a microprocessor, stores display information therein. The RAM is addressed by the display circuitry during the display cycle.

Abstract: Binary patterns that define alphanumeric characters for display are stored in a character pattern memory in a size that is smaller than the pattern that will be needed for display purposes. Each such stored character pattern is expanded to the size of a display character pattern, at a time when that character is to be displayed, on a point by point basis of the stored pattern. The expansion of each point in a stored character pattern is accomplished by a relationship that takes into consideration the points surrounding the point to be expanded.When a character requires a binary pattern that is not readily susceptible of this type of expansion, the full display size pattern must be stored in memory. This display size pattern is broken up into a plurality of smaller stored patterns and stored in memory as a plurality of adjacent smaller patterns. In effect, then, two different character pattern sizes are stored in memory.