HP-32S RPN Scientific Calculator, 50th Anniversary Limited Edition, 1989
The HP-32S was a simple Reverse Polish Notation (RPN) calculator, originally code-named "Leonardo." (RPN is a system for representing mathematical expressions without the use of parentheses.) Due to the broad range of functions, coupled with the $70 introduction price, the HP-32S was a popular calculator for science and engineering students.
This HP-32S was a special limited edition run for the 50th anniversary of HP in 1989.