The HP 49/50 series are Hewlett-Packard (HP) manufactured graphing calculators. They are the successors of the popular HP 48 series. There are five calculators in the 49/50 series of HP graphing calculators. These calculators have both algebraic and RPN entry modes, and can perform numeric and symbolic calculations using the built-in Computer Algebra System (CAS), which is an improved ALG48 and Erable combination from the HP 48 series. HP 49G Released in August 1999, the HP 49G (F1633A, F1896A) calculator was the first HP unit to break from the more traditional subdued coloration. In addition to having a metallic blue color, the keyboard material was rubber and did not have the traditional HP calculator hinged keyboard feel. In addition, it lacked a large key which was seen by many as the defining characteristic of an HP calculator. These changes were disliked by many traditional HP calculator users. The 49G incorporated many of the most powerful interface and mathematics tools available on the HP 48 series into the firmware of the new 49G, including the ability to easily decompile and compile both SysRPL and Saturn assembly code on the unit. The 49G was the first HP calculator to use flash memory and have an upgradable firmware. In addition, it had a hard sliding case as opposed to the soft pouches supplied with the HP 48 series. Almost the same hardware is also used by the HP 39G and HP 40G. The last officially supported firmware update for the 49G calculator was 1.18, but several unofficial firmware versions were released by the developers. The final firmware version was 1.19-6. Several firmware versions for the successor hp 49g+ and HP 50g calculators have also been released in builds intended for PC emulation software that lacked full utilization of the successors' ARM CPU. Until at least firmware version 2.09, those emulator builds could be installed on the original HP 49G. In 2003, the CAS source code of the 49G firmware was released under the LGPL. In addition, this release included an interactive geometry program and some commands to allow compatibility with certain programs written for the newer 49g+ calculator. Due to licensing restrictions, the recompiled firmware cannot be redistributed. hp 49g+ In August 2003, Hewlett-Packard released the hp 49g+ (F2228A). This unit had metallic gold coloration and was backward compatible with the HP 49G. Instead of the rubber keyboard found on the HP 49G,