The print manager window opens. It may appear uninteresting blank but down the bottom edge it says "N printers - N Hidden" where N is about 14. To see the printers follow View and "Select Printers to Show". Click printers which are of interest to you from the list "Hidden Printers" and then on the arrow to LHS to move them to the list of "Shown Printers"
The printer "_default" is the sparc's default printer - not your personal one.
To set your personal default printer move it to the "Shown Printer" list. Once there click on printer icons such that one and only one printer (your preference) is highlighted. The button "Set Default" is now enabled. Click on it and the highlighted printer becomes your personal default.
This is confirmed by the modification of the text on the top of the window which will now say "Default Printer: hp-Na" or whatever rather than simply "_default".
Click on OK to dismiss the Print Manager window.
setenv LPDEST hp-5aThe above example is obviously for queue hp-5a only. Log out and log in again for this to take effect.
The system default is specified in /etc/printers.conf