HP LaserJet 8000 Multifunction Printer series - Manual (Page 328)

Appendix D Printer Commands 328
Common PCL Printer Commands
Page Control Commands
Paper Source ?&l#H 0 = prints or ejects current page
1 = Tray 2
2 = manual feed, paper
3 = manual feed, envelope
4 = Tray 1
5 = Tray 3
7 = auto select
8 = Tray 4
20 = Tray 5
21-69 = external trays
Function Command Options (#)