Can the HP JetDirect J3113A interface be configured as a Line Printer
Daemon using port 515?
Yes. (Future reference: that's a JetDirect 600N.)
LPD should be enabled by default. If it's been turned off, you can use
a web browser to get to the JetDirect's configuration pages. Under
Networking, Configuration, Other Settings, make sure LPD Printing is
checked, then click Apply.
Or just telnet to it and type
lpd:1
exit
and save settings.