Printronix MVP Series user manual Introduction, Raster Plotting

Introduction

MVP–Series printers can produce bit image graphics in two modes: Raster Plot Mode and Bit Image Plot Mode. Both outputs are printed a dot row at a time, from top to bottom. The major difference between the two methods is the way the software manipulates the received data before output.

Raster plotting prints horizontal dot patterns corresponding to stored ASCII character code true or 1 bits. In bit image plotting, the stored code prints in vertical dot patterns because the print wires are arranged vertically.

P–Series compatible Odd/Even Dot Plot mode is only available in P–Series printer protocol. Since plot mode can address and print any individual dot position, it is possible to produce a variety of graphics, including bar codes, complex curve graphs, pie and bar charts, block characters, or halftones.

To initiate special plotting features use the appropriate control sequences described in following sections. Some control sequences require that the software contain configuration options, coordinated with specific control codes, before they can provide the desired printer output.

Raster Plotting

Raster plot data is sent to the printer as “printable” ASCII characters. Each printable ASCII character has seven–bit binary code associated with it. There are 96 printable ASCII characters (see Table 5–1), starting with SP (space) decimal code 32, through DEL (delete) decimal code 127. Included in the set are the ten digits (0–9), the upper and lower case alphabet (A–Z and a–z) and the various punctuation and other characters normally available on a standard keyboard.

Dot patterns obtained using the raster plotting feature correspond to the least significant six bits of each seven–bit code. That is, a dot is typed for every bit set (every “1”) in the ASCII code, except the seventh, or most significant bit. The dot pattern progresses from left to right with the leftmost dot set by the least significant bit (LSB).

5–2 Graphics