| 摘要 |
The characters are produced electronically through the implementation of character instructions which are stored in a memory in the form of a series of binary words. Each binary word is an instruction for producing a single straight-line portion, or stroke, of a complete character. Each such instruction word contains a count portion, which identifies the length of the stroke, a slope portion, which identifies the slope of the stroke, and a visibility portion, which identifies the visibility of the stroke. The character generator includes a counter which is preset to the amount of the count portion of each instruction word. The counter is counted down by a clock operating at a predetermined frequency. The slope portion of each instruction word is converted by a decoder into its respective X and Y component parts. These X and Y components are then applied to separate data channels which include adder/subtractor units under the control of the clock. A cumulative voltage signal is produced by each data channel and is applied to electron beam deflection circuits, which control the movement of the beam accordingly to construct the desired character.
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