HP L 5 manual Using a ROP, CMY ROP Truth Tables

Table 5-2. CMY ROP Truth Tables

	ROPcmy 252						ROPcmy 90							ROPcmy n
	(00000011)						(10100101)					n=(b7b6b5b4b3b2b1b0)
T		S	D	D		T		S	D	D		T	S		D	ROP n	D
0		0	0	0	white	0		0	0	1	white	0	0		0	b	!b7
																7
0		0	1	0		0		0	1	0		0	0		1	b6	!b6
0		1	0	0		0		1	0	1		0	1		0	b5	!b5
0		1	1	0		0		1	1	0		0	1		1	b4	!b4
1		0	0	0		1		0	0	0		1	0		0	b3	!b3
1		0	1	0		1		0	1	1		1	0		1	b2	!b2
1		1	0	1		1		1	0	0		1	1		0	b1	!b1
1		1	1	1	black	1		1	1	1	black	1	1		1	b	!b0
																0

Using a ROP

The first step in using a ROP is to determine which color space you're in: RGB or CMY. Then determine the binary value of the ROP used. For example, suppose you want to use ROP 90 in the CMY color space. The binary equivalent of 90 is 01011010 when written in most significant to least significant bit order.

Looking at the truth table for ROP 90 in Table 5-2 you can see that the only time the page is marked is when the Texture and Destination are both “0” or both “1.” However, the same result is given by negating each bit of the ROP number, 90, to give 10100101. Using the general table for CMY ROPs (the rightmost table in Table 5-2) you can plug the bit values from 90 into b7 through b0 to obtain the values in the truth table for ROP 90. Similarly, using ROP 90 in the RGB color space entails plugging 01011010 in the general table for RGB ROPS (the rightmost table in Table 5-1) to obtain the values in the truth table

for ROPrgb 90 (also in Table 5-1). This process works for any value from 0 to 255 and can be used to determine what will show for any

given ROP, in either the RGB or CMY color spaces.

5-16 The PCL Print Model EN