HP LaserJet 4050 Printer series - Manual (Page 226)

C-2 Printer Memory and Expansion
EN
The printer has two enhanced input/output (EIO) slots for
expanding the printer’s capabilities with:
•
A network card.
•
A mass storage device, such as a hard disk.
For ordering information, see page 9.
To find out how much memory is installed in the printer, or to find
out what is installed in the EIO slots, print a configuration page
(page 134).