Hewlett-Packard HP49 2 x TOSEC

"The HP 49G series are Hewlett-Packard (HP) manufactured graphing calculators. They are the successors of the HP-48 series, one of the best-selling calculator ranges among engineers, scientists, and students.

There are now four calculators in the 49 series of HP graphing calculators. These calculators all have both algebraic and RPN entry modes, and can perform numeric and symbolic calculations