There are three ways to print to a serial printer:

1) Most recommended way: Print Manager

A) Terminal -> Setup -> Printer tab

B) Set Print Device to "Print Manager"

C) Click on "Advanced Printing" button, and set the "Printer Type\Model" to one of the dot-matrix printers on the list (for example one of the DFX printer types).

D) Save the changes, and select the desired port.

2) Aux:

A) Terminal -> Setup -> Printer tab

B) Set the "Print Device" to "Aux"

C) Click OK

D) Communications -> Utilities -> AUX: Modify Connection

E) Select the desired COM configuration

3) Print Device - COM

A) Terminal -> Setup -> Printer tab

B) Set "Print Device" to "Device"

C) Type the desired port ("Device Name") - For example: COM1

D) Click OK.