IBM InfoPrint 6500, User Manual

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Printing Speed
The speed of text printing is measured in lines per minute (lpm). This speed is
dependent upon the number of dot rows required to produce a line of characters,
regardless of the number of characters in the line. Because more dot rows are
required to print lowercase characters with descenders, those character lines will
print at a fractionally lower rate.
In addition to character printing, the printer can plot dot-addressable graphic
images. The speed of graphics plotting is measured in inches per minute (ipm).
Unidirectional plotting can produce better print quality and takes about twice as
long as bidirectional plotting. You can select either plotting mode from the
operator panel or from the host computer.
Printing rates also vary according to the print quality you select. For example, if
you select the Near Letter Quality (NLQ) option, the printer uses more dot rows
and slower print strokes to form characters than if you choose the Draft Quality
option. Character formation and print speed are faster in Draft Quality because the
printer uses fewer dot rows to form characters.
Printing rates are listed in Appendix A, “Printer Specifications,” on page 249.
Appendix B. A Quick Look at Line Matrix Printing
263