IBM Partner Pavilion 6400 - Manual (Page 26)

12 Multi–Platform Interface Feature Operation Guide
Configuring for port switching
If you will be port switching with the MPI,
you must set the printer emulation used by
the PC application to match the emulation
you have set in the printer.
For example, when you have set the printer
emulation to 6400-Epson, your host ASCII
application, should use a standard Epson
print driver.
When you have set the printer emulation to
the P-Series emulation, your application
should use a standard P-Series printer
driver.