The HP-48 is a series of graphing calculators using Reverse Polish notation (RPN) and Reverse Polish Lisp (RPL), produced by Hewlett-Packard (HP) from 1990 until 2003. The 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. The models with an X suffix are expandable via special RAM (memory expansion) and ROM (software application) cards. In particular, the GX models have more onboard memory than the G models. The G+ models have more onboard memory only. The SX and S models have the same amount of onboard memory.
Note that the similarly named HP-48GII (2004) is not really a member of the series, but rather much more closely related to the HP-49G and HP-49G+.
The hardware architecture developed for the HP-48 series became the basis for the HP-38G, with a simplified user interface and an infix input method, and the HP-49G with various software enhancements. Likewise, the hardware and software design of the HP-48 calculators are themselves strongly influenced by other calculators in the HP line, most of all by the HP-18 and HP-28 series.
More on [ HP-48 series ]

ALG48 Library Page - Libraries on this site: ALG48, RSIM, and AIO48.
404
Andr Schoorl's - HP48 calculator programs. The interests here are programs and related items for system RPL and assembly language programming as well as symbolic math.
Doug Cannon's HP48 Page - HP48 calculator programs, programming tips, source code, and other information.
Meta Description: [ Dougc's favorite HP48 files & links ]
Frequently Asked Questions About the HP49 - Information about the HP49G, HP's latest calculator still in development.
Meta Description: [ Frequently asked questions about the HP49G calculator as part of the HP Calculator Archive ]
hpcalc.org - Premier website for program that run on the HP48, HP38 and HP28 series of calculators Formerly known as hp48.ml.org
Meta Description: [ The largest, best source on the Internet for software for and information about Hewlett Packard's HP49G, HP48, HP38G, and HP28 graphic calculators. ]