Brother HL-7050N - Manual (Page 121)

3 - 37 CONTROL PANEL
HL7050_US_UG_FM5.5
HP-GL Mode
The HP-GL mode is the emulation mode in which this printer
supports the HP-GL language of the Hewlett-Packard plotter model
HP-7475A. Many graphics and CAD applications support this type
of plotter. Use this mode so your printer will work when printing from
those types of applications.
EPSON FX-850 and IBM Proprinter XL Mode
The EPSON FX-850 and IBM Proprinter XL modes are the emulation
modes that this printer supports to meet the industry-standard for dot
matrix printers. Some applications support these dot matrix printer
emulations. Use these emulation modes so your printer will work
well when printing from those types of applications.