SU1056258A1 - Sign generator - Google Patents

Abstract

SIGNS GENERATOR containing a block of permanent memory,. row counter and point counter, which means that, in order to simplify the character generator by reducing the volume of the PERMANENT memory, it contains a group of elements 2I-OR, element 2I-G-OR-NOT And the element AND whose output is connected to the control input of the fixed memory unit, and the first and second inputs are connected respectively to the control input of the point counter and the output of the element 2I-OR-NOT, the inputs of which are connected to the corresponding bit outputs of the point counter and the inputs of the first group of inputs of elements 2I-OR group, in Dates of the second group of groups are connected to the corresponding bit outputs of the row counter, the outputs of elements 2I-OR of the group are connected to the corresponding bit inputs of the fixed memory unit. (L

Description

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The invention relates to computing and can be used in information display devices on cathode ray tubes.

A well-known character generator containing a block of permanent memory, a row counter and a point counter {ll}

The closest in technical essence to the invention is a character generator comprising a block of permanent memory, a row counter and a point counter 2.

The disadvantage of these sign generators is the excessive amount of the storage unit used in them. , The aim of the invention is to simplify the sign generator by mixing the volume of a fixed memory block.

The goal is achieved by the fact that the character generation, which contains a PERMANENT memory block, a row counter and a point counter, contains a group of 2I-OR elements, 2I-OR-HЁ element and AND element, the output of which is connected to the control input of the fixed memory block. These first and second inputs are connected, respectively, to the control input of the point counter and the output of the 2Y-OR-NOT element, whose inputs are connected to the corresponding bit outputs of the point counter and the inputs of the first group of inputs of the 2I-OR group, the inputs of the second group of connection us with corresponding raar dnymi line counter outputs, Vyg elements go 2I-OR group of the compound with the corresponding bit inputs of the block dnymi permanent memory,

The drawing shows a functional diagram of a symbol generator.

The character generator contains a block of 1 constant memory, a counter of 2 points, a counter of 3 lines, elements 2I-ILY 4 groups, an element 2I-OR-NOT 5, and an element AND 6.

The character generator works as follows.

The number of characters and information that support the display is less than or equal to 96, i.e. 7 is necessary and sufficient for coding enaks

binary bits (128 code combinations). The unfolding of the information mark is done on point methods in 9 lines x (7 + 2) points (7 points used to display the character element in the line, 2 points needed to separate the characters in the line). Thus, a point is needed to display the sign, which is determined by the binary bits (64 codewords).

The conversion of the demo-bit code of the 9x7 display matrix (4 bits of the 3-row counter and 3 low-order bits of the 2-t6 counter) is performed using the elements 2I-OR 4 groups.

The following point counter codes 2: 000, 001, 010, 011, 100, 101, 110; those. code 111 is not used. The rows in the character mapping matrix are encoded with the following 3 row counter codes: 0000, 0001, 00.10, UN, 0100, 0101, ITO, 1000, i.e., a fourth digit is required on the row counter to represent a 1000 combination. The reduction in the number of bits for coding points in a 9x7 matrix is accomplished by replacing the 1000 code of the 3 line counter with the 111 code of the 2 point counter.

This replacement is presented in the table.

Considered functional coding transformation of points in the matrix is optimal and. used in the present invention. In order to prohibit the operation of the device in the intervals between the characters of the information display, elements 2I-OR-NOT 5 and AND 6 are used. The operation of elements 5 and 6 prohibits the excitation of the block 1 of the permanent memory with the codes on the point counter 0111,1000. These codes are used to display the gaps between the information signs.

 Since the number of bit inputs of block 1 of the permanent memory is reduced by one input, this leads to a two-fold reduction in the volume of block 1.

The data is a combination of codes

Converted code combinations

: Counter Outputs

Point row count output

000 001 010 011 100 101 110

Counter values: t Counter points t tick value

111 111 111 111 111 111 111

Claims (1)

SIGNS GENERATOR, which contains a read-only memory block, a line counter and a dot counter, so that, in order to simplify the character generator by reducing the size of the read-only memory, it contains a group of 2-OR elements, element 2I- + OR-NOT and element AND, the output of which is connected to the control input of the read-only memory unit, and the first and second inputs are connected respectively to the control input of the point counter and the output of element 2I-OR-NOT, the inputs of which are connected to the corresponding bit outputs point counter and first inputs of the second group of inputs of the elements of the II-OR group, the inputs of the second group of which are connected to the corresponding bit outputs of the line counter, the outputs of the elements of the II-OR group are connected to the corresponding bit inputs of the read-only memory block. Word □ o> 1056 258