Xerox DocuPrint C55 Supplementary Manual page 346

Where:
<port> = the parallel port to which the printer is connected
(LPT1:,LPT2:, etc.)
<filename> = the path and name of the upgrade file
Ex: copy 3_3_4.xfc LPT1
5. The file will be sent to the printer. To see if your upgrade was
successful see the section labeled Determining a Successful Upgrade.
If successful follow the instructions in After the Upgrade.
IF YOU HAVE PROBLEMS:
Make sure you are using a IEEE P1284 compliant cable such as
the one shipped with the C55 printer.
Make sure the printer's parallel port Mode is set to AutoSelect
for C55 mp printers, or printers with the PostScript option.
If running a DOS window from Windows 95 make sure that one
of your printers through Settings/Printers is mapped directly to
LPT 1(not re-directed to a network queue). Also check the port
settings by selecting the Port Settings.. button on the Details tab
dialog. Make sure the selection Spool MS-DOS Print Jobs is
selected. After making these settings try powering off an on your
PC if still having problems.
(Windows Users) If experiencing time-outs on the host PC
("Problem detected on parallel port, Abort,Retry,Fail") then you
need to set the port to an infinite time-out against busy on the
printer. From the command line or as an entry in autoexec.bat
type the following command:
mode lpt1:,,b (two commas following the colon)
The "b" option sets the port for infinite time-out. After setting
the port to an infinite time-out, try using the copy command
again. If the command prompt does not appear within 15 minutes
a ctrl-break can be used to abort the copy command without
rebooting your computer.
Windows 3.11 users should turn off Print Manager.
In addition consult the section labeled General Troubleshooting
S Y S T E M M A I N T E N A N C E 23