IBM RT Series Hardware Reference Manual page 351

TNL SN20-9844 (March 1987) to 75X0235
Read Modify Write Destination (X'2F')
This graphic operation type read-modify-writes a rectangular area of pels in the bit map. Only
one subtype is specified via the LF bits as listed below.
Rectangular XOR Destination LF
=
9,'" Destination
=
Result Destination
...... _ _
R_EV_E_R_S_E_V_I_D_EO_C_H_A_RA_C_T_E_R_L_IN_E_~}
lOY) " 20
(X, Y) LOWER RIGHT CORNER
~
_ _ _ _ _ _ --,-_ _ _ _ _ _ ----,I
(768,20) EXCLUSIVE
~--------(DX)=768
Figure 26. Reverse Video Character Line (X = 768,Y = 20,DX = 768,DY = 20)
Extended Monochrome Graphics Adapter
39