The HP-48 is a series of graphing calculators produced by Hewlett-Packard (HP) from 1990 until 2003, using Reverse Polish notation (RPN). The HP-48 series include the HP-48S, HP-48SX, HP-48G, HP-48GX, and HP-48G+, the G models being expanded and improved versions of the S models.
For sure the best calculator ever made
I am still (since 1991) the proud owner of: Hp48Gx - HP48S - HP42s - HP20s
Stuff i did program when at school
My collection of HP calculator, I did never sell my first HP calculator since 1991