IBM RT Series Hardware Reference Manual page 350

TNL SN20-9844 (March 1987) to 75X0235
Write Destination (X'2F')
This graphic operation type writes a rectangular area of pels in the bit map. Three subtypes are
specified via the LF (graphic op logic function) bits as listed below.
Rectangular fill replace off:
Rectangular XOR destination:
Rectangular fill replace on:
LF
=
0, Set destination to
°
LF
=
9, Msk
=
destination (Reverse video)
LF
=
F, Set destination to 1
'--_ _ _ C_L_E_A_R_C_H_A_R_A_C_T_ER_Ll_N_E _ _ _ _
}IOYI
=
20
(X, V) LOWER RIGHT CORNER
'--_ _ _ _ _ _ ~----------'I
(768,20) EXCLUSIVE
' - - - - - - - - - - - - ( D X ) =768
Figure 25. Clear Character Line (X
=
768,Y
=
20,DX
=
768,DY
=
20)
38 Extended Monochrome Graphics Adapter