
2–33
When the upper left corner of the cursor is preferred as a reference, determine the screen (x,y) coordinate
where cursor (0,0) is to be positioned. Then add 64 (0x40) to the x coordinate and add 64 (0x40) to the y
coordinate and write these values to the cursor position (x,y) registers. For example, when the upper left
corner of the cursor is to be positioned at screen (0,0), write (0x40, 0x40) to the cursor (x, y) registers.
BLANK
X
Y
Active Display Area
64
×
64 Cursor Area
Cursor Position (X, Y)
Cursor (0,0)
Screen (0,0)
B
Cursor Position (X,Y) = Screen (X,Y) Where Cursor (0,0) is Located + (64,64)
Figure 2–9. Cursor Positioning
2.7.3
The 64 x 64 x 2 cursor RAM provides two bits of cursor information on every dot clock cycle during the
64 x 64 cursor window. CCR1 and CCR0 specifiy whether the XGA mode (10) or X-window mode
(11) or 3-color mode (01) interprets the cursor information. When CCR1 and CCR0 are 00, the cursor is
disabled. The cursor enable/disable and mode select may also be programmed using the direct cursor
control register. The two bits of cursor pixel data determine the cursor appearance as shown in Table 2-22.
Three-Color 64 x 64 Cursor
Table 2–22. Cursor RAM Vs. Color Selection
RAM
COLOR SELECTION
PLANE 1
PLANE 0
THREE-COLOR
MODE
XGA MODE
X-WINDOW MODE
0
0
Transparent
Cursor color 0
Transparent
0
1
Cursor color 0
Cursor color 1
Transparent
1
0
Cursor color 1
Transparent
Cursor color 0
1
1
Cursor color 2
Complement
Cursor color 1
Cursor color 0, 1, and 3: These colors are set by writing to the cursor-color registers.
Transparent: The underlying pixel color is displayed.
Complement: The 1s complement of the underlying pixel color is displayed.