UPPERCASE_DRIVE_FOR_TV_GRAPHICS

Published:2009/7/5 22:25:00 Author:May | From:SeekIC

Alphameric data-to-video converter using 2513 character generator accepts ASCII words from microprocessor memory and three line commands from instruction decoder. Five dots are outputted simultaneously, corresponding to one row on 5 x 7 dot-matrix character. 7416S eight-input one-output shift register converts dots into serial output video. Input repeats to generate all seven dot rows in row of characters. Shift register is driven by high-frequency timing circuit that delivers LOAD pulse once each microsecond along with CLOCK output running continuously at desired dot rate. Optional cursor uses 4584 5-Hz oscillator for cursor winking rate. If ASCII input bit 8 is high, cursor input goes high and output is white line on leads 01 through 05. Right diode mades this line blink, while Ieft diode allows winking cursors only during valid character times.-D. Lancaster, TVT Hardware Design. Kilobaud, Jan. 1978, p 64-68.



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