Epson Research and Development
Page 55
Vancouver Design Center
8.5.4 Move Cursor in SwivelView 270° Rotation
In the following example, (x, y) represent the desired cursor position.
1. Calculate the value of x2,
where x2 = display width - x - 64
2. Calculate abs(x2), the absolute (non-negative) value of x2.
3. Write the least significant byte of abs(x2) to Y Position Register 0.
4. If x2 is negative, take the value of the most significant byte of abs(x2) and logically
OR with 80h. Write the result to Y Position Register 1.
If x2 is positive, write the most significant byte of abs(x2) to Y Position Register 1.
5. Calculate abs(y), the absolute (non-negative) value of y.
6. Write the least significant byte of abs(y) to X Position Register 0.
7. If y is negative, take the value of the most significant byte of abs(y) and logically OR
with 80h. Write the result to X Position Register 1.
If y is positive, write the most significant byte of abs(y) to X Position Register 1.
Programming Notes and Examples
Issue Date: 01/02/06
S1D13506
X25B-G-003-03
EPSON [ EPSON COMPANY ]
