The computer system of this invention has, as the heart of the system, a simple processing unit for providing most data processing by the computer system under control of a read-only memory which contains only instructions and other data for the CPU. The system also includes a random access memory, a keyboard, a video terminal, and a port device in the form of a tape recorder/player. A master clock initiates timing used throughout the system. A multi-line data bus interconnects the CPU and the different memories of the system including the keyboard and the video RAM. Bi-directional communication is possible on the data bus. The addressing of these different memories is by way of an address bus from the CPU, which is a uni-directional bus. Data to be operated upon is basically stored in the random access memory. The keyboard is used for inputting data to the CPU and the video terminal is used for displaying data. Features of the present invention include a special reset scheme for the CPU, a multiplexing scheme for addressing the RAM, a technique for simply altering the control to provide capabilities of different capacity memories, alternate display of characters to provide, for example, either a 32-character line or a 64-character line, an improved keyboard selection scheme, and improved video processing means.
This application is a division of application Ser. No. 342,069, filed 1-25-83, now U.S. Pat. No. 4,500,956 which is a division of Ser. No. 261,976, filed 5-8-81 now U.S. Pat. No. 4,430,649, which is a continuation of Ser. No. 926,957, filed 7-21-78, now abandoned.
A method for reading a position of a wiper on a potentiometer, comprising the steps of (A) charging a capacitor connected to a wiper terminal of the potentiometer, (B) discharging the capacitor through a particular terminal of the potentiometer, (C) measuring a first time taken to discharge the capacitor from a first voltage to a second voltage, (D) recharging the capacitor, (E) discharging the capacitor through another particular terminal of the potentiometer, (F) measuring a second time taken to discharge the capacitor from the first voltage to the second voltage, (G) reading the position of the wiper by calculating a ratio of the times measured in steps (C) and (F).
A Memory Interface and Video Attribute Controller (MIVAC) is inserted between a dynamic RAM (DRAM) capable of a consecutive data read operation, such as the operation associated with the static column mode, page mode, or nibble mode, and a graphic processor to provide a parallel data processing. A serial data transfer is executed on each data bus between the MIVAC and the DRAM, whereas parallel data transfer is conducted between the MIVAC and the graphic processor. As a result, the graphic processor can be configured with a reduced number of DRAMs so that the graphic processor operates without paying attention to the consecutive data read mode of the DRAM.
A method for reading a position of a wiper on a potentiometer, comprising the steps of (A) charging a capacitor connected to a wiper terminal of the potentiometer, (B) discharging the capacitor through a particular terminal of the potentiometer, (C) measuring a first time taken to discharge the capacitor from a first voltage to a second voltage, (D) recharging the capacitor, (E) discharging the capacitor through another particular terminal of the potentiometer, (F) measuring a second time taken to discharge the capacitor from the first voltage to the second voltage, (G) reading the position of the wiper by calculating a ratio of the times measured in steps (C) and (F).
A control circuit for controlling a driving circuit that provides signals to a displaying means, wherein a function of outputting a plurality of digital signals at different phases is included, and said phases can be set by selective elements.
The present invention relates to display adjustment and balance methods for liquid crystal displays, LCDs. A wide-range display position adjustment method is described. Compared with the prior art liquid crystal display controllers, the embodiments of this invention are not limited by the width of the vertical and horizontal front and back porch regions of the timing diagrams. These porch values are a function of the display chip technology. The display location control of this invention is independent of the limits of the front and back porch times. The embodiments of this invention facilitate the design of a display position control circuit which allows the image display to be rolled around anywhere on the panel.
