Epson Y16499100301 - Manual (Page 24)

Serial interface
If you have a printer or another peripheral with a serial
interface, connect it to the serial (RS-232C) port at the back of
the computer.
The Equity LT uses a DB-9P connector, so be sure you
have an IBM AT-compatible cable (or an adapting cable that
converts the 9-pin output to the standard 25-pin output). To
connect a serial device, follow the same steps given above for
connecting a parallel device.
You need to ensure that the serial port is set up to
function properly. If you are using the port for a serial printer,
you must also redirect printer output to the serial instead of
the parallel port. To make these changes, use the MS-DOS
SETMODE program (or the MODE command), described in
your MS-DOS manual.
Setting Up Your System 1-9