KR920001309A - Font Data Read / Write Device of Video Card - Google Patents

Abstract

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Description

Font Data Read / Write Device of Video Card

As this is a public information case, the full text was not included.

(A) of FIG. 1 is a video buffer use area on the CPU memory for each video card.

(B) of FIG. 1 is a video buffer address display diagram in which a font window (FONT WINDOW) is located.

2 is a block diagram showing a schematic configuration of the present invention.

Claims (2)

A device for reading and writing fonts (FONT) of a video card; Decoder means 21 connected to an address / control bus, a signal connected to the decoder means 21 and output through first and second input / output ports And reset signals A first input / output port of the selection control means 22, the data bus and the decoder means 21 for generating a selection control signal using A first buffer 23a and a second input / output port of the data bus and the decoder means 21 connected to the first buffer 23a. A buffer means 23 composed of a second buffer 23b connected to the character means, a character select means 24 connected to the buffer means 23 to input a font address and output a character select address, the address / control bus and A control signal of the selection control means 22 connected to an output terminal of the selection control means 22 Decoder and font selecting means 25 for switching the font window on the CPU memory in accordance with the character font memory 26 connected to the character selecting means 24 and the decoder and font selecting means 25, and the decoder and CPU memory 27, which is connected to the font selecting means 25 and includes a ROM BIOS area and a video buffer area, which comprises a selection address of the character selection unit 24 and an output signal of the decoder and selection unit 25. A font data read / write device for a video card, characterized in that the specified hint window is switched to appear in an unused specific area on the CPU memory. The second input / output port according to claim 1, wherein said selection control section (22) is a second input / output port of the decoder means (21). First input / output port of the first AND gate 203 and the decoder means 21 for inputting and ANDing the output signal and the reset signal. A second AND gate 204 for inputting and ORing an output signal and a reset signal, and the first and second input / output ports. A third AND gate 206 for inputting and ANDing an output signal and the first input / output port A first D flip-flop 201 and a second input / output port to which a clock input terminal is connected, a clear terminal is connected to an output terminal of the first AND gate 203, and a data input terminal is connected to a power supply terminal. A 2D flip-flop 202, a first and a second D flip-flop 201, 202 connected to a clock input terminal thereof, a clear terminal connected to an output terminal of the second AND gate 204, and a data input terminal connected to a power supply terminal thereof. An XNOR gate 205 having an input coupled to a positive output stage, the first D flip-flop sub-output stage, and a first input / output port And a thirteenth input OR gate 207 connected to an output terminal of the XNOR gate 205, the second D flip-flop sub-output terminal, and a second input / output port. And a fifth AND gate connected to an output terminal of the twenty-third input OR gate 208 connected to an output terminal of the XNOR gate 205, an output terminal of the fourth AND gate 209 connected to an output terminal of the first and twenty-third input OR gates 207, 208, and 210, and a clock input terminal is connected to an output terminal of the third AND gate 206, a clear terminal is connected to an output terminal of the fifth AND gate 210, a data input terminal is connected to a power supply terminal, and a selection control signal is connected through a sub output terminal. 3D flip-flop (211) for outputting the font data reading / writing device of the video card. ※ Note: The disclosure is based on the initial application.