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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 (0-39), 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.

SETTING CURSOR LOCATION
  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
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