B-19. Function Name: PLOT

Purpose: Set cursor location
Call address: $FFF0 (hex) 65520 (decimal)
Communication registers: A, X, Y
Preparatory routines: None
Error returns: None
Stack requirements: 2
Registers affected: A, X, Y

Description: A call to this routine with the accumulator carry flag set loads the current position of the cursor on the screen (in X,Y coordinates) into the Y and X registers. Y is the column number of the cursor location (6-39), and X is the row number of the location of the cursor (0-24). A call with the carry bit clear moves the cursor to X,Y as determined by the Y and X registers.

How to Use:

READING CURSOR LOCATION

1. Set the carry flag.
2. Call this routine.
3. Get the X and Y position from the Y and X registers, respectively.

1. Clear carry flag.
2. Set the Y and X registers to the desired cursor location.
3. Call this routine.

EXAMPLE:

   ;MOVE THE CURSOR TO ROW 10, COLUMN 5 (5,10)
   LDX #10
   LDY #5
   CLC
   JSR PLOT