The HP-42S was released as a replacement for the aging HP-41 series, and is designed to be compatible with all programs written for the HP-41. However, it has received criticism for its lack of expandability, and lack of any real I/O ability, both key features of the HP-41 series. The 42S, however, has a much smaller form factor than the 41, and features many more built-in functions, such as a matrix editor, complex number support, an equation solver, user-defined menus, and basic graphing capabilities. Additionally, it features a two-line dot matrix display, which made stack manipulation easier to understand. Production of the 42S ended in 1995.
This unit includes user's manual (English or Spanish - your choice), vinyl case and original box with inner plastic.