Apparatus for dot-matrix printing with proportional character spacing

An apparatus for dot-matrix printing of characters for use with an input device and an incrementally advanceable printer carriage comprising:

• a character generator in which said characters are stored in binary bit form in respective matrices of columns and rows, said matrices being of equal size regardless of the actual width of characters stored therein such that a plurality of columns in a number of said matrices are unoccupied by character bits, one incremental advance of said printer carriage normally corresponding to one column in the storage matrix of a character to be printed;
• a character control unit connected to said input device and to said character generator, said character control unit operable in a fixed character spacing state and a proportional character spacing state depending upon the type of character to be printed as received from said input device;
• and
• a printer control unit connected to said character control unit for controlling the incremental advancement of said printer carriage, said printer control unit operable, when said character control unit is in said proportional character spacing state, for initially advancing said printer carriage by a first fixed number of increments, inhibiting advancement of said printer carriage until an occupied column in said storage matrix, advancing said printer carriage in single-column increments for columns in the storage matrix of a character to be printed which are occupied by a character bit, and for advancing said printer carriage a second fixed number of increments for the total number of unoccupied columns remaining in the respective storage matrix for a character.