Lexmark FORMS 249X Technical Reference page 62

The barcode type is denoted by k. The following values are valid for k:
Module width is denoted by m. When m is 1, the barcode prints by
1/360 or 1/240 full dot method. For all other values, the barcode prints by half
dot method. The suggested values for m are as follows:
The variable s denotes the space width adjustment and affects the barcode
printing width. The value for s may range from 3 (03 hex) to -3 (FD hex),
however, 0 is the default value. The adjustment unit for 24 wire printers is
1=1/360 in. and for 9 wire printers the unit is 1=1/240 in.
The variables v1 and v2 control the bar length. The minimum value of v1, v2 is
288 dec (24 wire) and 270 (9 wire).
62
Section 3: IBM Emulation Mode Printer Commands
k
Dec Hex
177 B1
178 B2
179 B3
180 B4
181 B5
182 B6
183 B7
184 B8
185 B9
186 BA
m
Dec Hex
0 00
1 01
2 02
3 03
4 04
Barcode Type
<reserved>
EAN-13
EAN-8
CODE 39
<reserved>
INTERLEAVED 2 of 5
UPC-A
<reserved>
POST-NET (barcode)
CODE 128
Unit Module
Dots
24 wire
0.015 in.
0.012 in.
0.015 in.
0.021 in.
0.026 in.
Width
9 wire
0.021 in.
0.017 in.
0.021 in.
0.030 in.
0.038 in.