HP L 5 manual Logical Operations and the Print Model

Assuming three bits per pixel, the following diagram shows the process.

Figure 5-4	Logical Operations and the Print Model
	The Logical Operation command (?*l#O) provides 255 possible
Note
	logical operations. All of these logic operations map directly to their
	ROP3 (raster operation) counterparts (see the Microsoft Document,
	Reference, Volume 2, Chapter 11, Binary and Ternary Raster
	Operation Codes).
	The logical operations were defined for Microsoft Windows for an
	RGB color space. In RGB space, a “1”' is white and a “0” is black.

EN The PCL Print Model 5-11