Yamaha V9938 Programmer's Manual page 86

Step 2: Set color register value
Color of the resulting line mask is coded in color register R#44 (CLR). Format of color
data depends on the graphics mode.
MSB
R#44
Step 3: Select destination memory, direction from base coordinate and orientation
Bit MAJ of the register R#45 controls which coordinate is defined in registers R#40-
R#43. If this bit is 0, then long side (NY) defines triangle's side by X-axis and short side
(NX) defines triangle's side by Y-axis; if this bit is 1, then long side (NY) defines triangle's
side by Y-axis and short side (NX) defines triangle's side by X-axis.
MSB
R#45
Step 4: Define logical operation and execute the command
MSB
R#46
Step 5: Check for command completion
CPU should check CE bit of status register S#2 to identify if VDP has completed
execution of the command. When command is being executed, CE bit is set to 1; when
command is complete, CE bit will be reset to 0.
© 1985 ASCII CORP. / NIPPON GAKKI CO.
7 6 5
- - -
- - -
C7 C6 C5
7 6 5
0 - MXD
7 6 5
0 1 1
4 3 2
- C3 C2
- - -
C4 C3 C2
4 3 2
- DIY DIX
4 3 2
1 LO3 LO2
Logical operation
Page 86 of 108
1 0 LSB
C1 C0 G4, G6
C1 C0 G5
C1 C0 G7
1 0 LSB
- MAJ
0: Long X Long/short
1: Long Y axis definition
0: Right X transfer
direction
1: Left
0: Down Y transfer
direction
1: Up
0: VRAM Destination
location select
1: ExpRAM
1 0 LSB
LO1 LO0 LINE cmd
© 2010-2015 Eugeny Brychkov