dot matrix

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A grid of dots or pins used to form characters or designs, as by some computer printers and visual display units.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective which prints by stamping an array of tiny dots onto the paper

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a rectangular matrix of dots from which written characters can be formed