This page documents a CAD program that I am developing to use with my CNC router. The program is intended to allow me to draw things and export my work as a DXF file. There are many free CAD programs out there and I am not recommending that you use this one. This is mostly indulging my hobby of writing code.
To add lines: First add points using the Add_Pt button then select point and press the "+PT" button, to remove points from line list, select point and press "-PT" button. A series of connected lines can be created by adding additional points to the line point list. When all of the points have been added, press ADD button to add lines to the drawing.
To remove a line, select two points at the ends of the line and press the "CUT" button