"Blackboard" calculator is protected by copyright laws and international copyright treaties.

1. You may install and use as many copies as you wish, on any number of computers.
2. You may distribute this software as long as the original archive remains intact.
3. You may NOT modify, reverse engineer, de-compile, or disassemble this software.
4. The sale of this software is strictly forbidden.

Any use by you of this software is at your own risk.
This software is provided for use "as is" without any warranty of any kind.
The author is not obligated to provide any updates to this software.