Epson LQ-850 Manuel D’Utilisation

Following the specification of the range of characters to be

defined in this command are three data bytes 

 that specify

the width of the character and the space around it. The left space

(in dot columns) is specified by 

 and the right space is specified

by 

 The second byte 

 specifies the number of columns of

dots that are printed to make up the character. By varying the
width of the character itself and the spaces around it, you can
create proportional-width characters that print at draft speed. The
table below shows the maximum values for these bytes.

The last part of the character definition is the actual data that

defines the dot patterns for each character. Since it takes three bytes

to specify the dots in one vertical column of dots, the LQ expects

 x 3 bytes of data to follow d2.