Improved Visibility Timeout Method
Original Publication Date: 1988-Dec-01
Included in the Prior Art Database: 2005-Feb-15
A technique for visibility (printer inactivity) timeout on a printer or typewriter places the time-out function within the device control logic and allows for multiple timeout levels based on keyboard input. Fig. 1 is a block diagram of the pertinent portion of the typewriter control logic. The dashed line indicates the interface between the device control logic which directly controls the typewriter hardware, and the function processing logic which directs the typewriter operation. (Image Omitted) Keyboard Control 10 detects key changes and transfers this information to be stored in keyboard surge buffer 11. A keyboard status register 12 is provided, and two of the flags in the keyboard status register 12 are a Surge Buffer Empty flag and a Graphic Pending Flag.