Most modern printers could be considered dot-matrix printers because they
print characters in a pattern of tiny dots. However, the term "dot-matrix" is
usually reserved for older printers that use a series of pins to push an inked
ribbon against the paper. These printers have a row of 7 to 24 pins which are
swept across the paper as solenoids push the appropriate pins against the ribbon
and paper.
An Epson MX-80
The Epson MX-80 was one of the most popular early desktop printers. It
retailed for $599.99. Early versions were ASCII only, but the "GraphTrax"
upgrade[1]
allowed dot-addressable graphics. It required tractor-feed paper. It could print
bold by "double striking" each print pin and print italic by hitting the pins in
succession.
Dot-matrix printers had ribbons on spools or cartridges (as the MX-80). The
following image shows a ribbon cartridge with the cover removed to show the
ribbon bunched up inside.
The ribbon cartridge for
dot matrix printer
Dot-matrix printers produced various print qualities depending on the number
of pins in the print head.
A sample of printing from
a dot-matrix printer like the MX-80
