IBM 1800409-001A - Manual (Page 98)

If the printer and computer are communicating, a blank page should
eject from the printer. You are ready to start printing.
If a blank page does not eject and you typed the file correctly, check
your AUTOEXEC.BAT file to see if LPT1 (the parallel port) is
being directed to COM1 (the serial port). If the AUTOEXEC.BAT
file contains the following line, delete it:
MODE LPT1:=COM1:
Then type
mode lpt1:,,p
in the AUTOEXEC.BAT file so that print jobs are sent until the
printer accepts them. Reboot and try the communication test again.
See chapter 9, “Troubleshooting,” and refer to your DOS
documentation for more information.
Chapter 3
3 - 1 8 C o n n e c t i n g t h e P r i n t e r