We have a barcode font generator program that might be helpful. The
program runs under MS-DOS and produces a downloadable soft font file.
This file can be copied to a laserjet (or any PCL-5 compatible printer).
Once that is done, you just send the PCL-5 command to switch fonts and
send the data.
Code 39 does not require a checksum; you just need to enclose the data
within asterisks, which translate to the Code 39 start/stop character. We
also have a generator for Code 128, which does require a checksum. The
generator lets you specify the bar width, height, and other parameters of
The generator programs are not free, but they are cheap ($35). Send me
e-mail if you would like more information, or check our page at
bar code specialists