Genicom GEK 00031B manual Six-Bit Graphics, Dot Patterns and Densities

GRAPHICS

The ANSI emulation graphics mode provides both horizontal and vertical dot plotting methods. These methods enable the printing of ASCII characters in their binary code form. Since each character has a unique pattern of 1s and 0s (dots and voids) that make up its binary code, the correct placement of these binary forms enables you to form larger images on the paper.

For clarity in the text, a binary 1 (a printed dot) is shown as an X and a binary 0 (empty dot position) will be shown as a 0.

Six-Bit Graphics

In the graphics mode, only the low order six bits of a character are used (bits 1-6). Looking at an ASCII code chart, the question mark

character (?) is represented by the binary number 1111110 (bit 1 - bit 7). Since only the first 6 bits are used. a "?" prints six dots on the paper. An asterisk "*" is represented by 010101 which prints the following:

Horizontal Graphics	Vertical Graphics
	0
	X
0X0X0X	0
	X
	0
	X

Notice that in horizontal graphics the character is printed on a single horizontal dot row. In vertical graphics, the character is printed six dots high, one character per dot column.

Using the question mark that prints all dots, a series of these characters in horizontal graphics produces a one-dot-high solid line across the paper. The same character in vertical graphics produces a six-dot high band across the paper.

By repeating, omitting and mixing characters across a page, images such as graphs, charts, and pictures can be produced.

Dot Patterns and Densities

The chart on the next page shows the dot patterns for each of the ASCII characters. Each character represents six dots or dot positions, and their spacing is dependent on the density selected. At 60 dpi density, the dots are spaced 1/60 inch apart. At 120 dpi, each character represents six dots spaced 1/120 inch apart.

Chapter 2. ANSI Emulation 36 GEK-00029B