this calculator's keyboard had plastic hinges intended to return the feel of older HP calculators, and also included a pouch to protect the unit, similar to those included with older HP models. It was designed and manufactured by Kinpo Electronics for HP. This calculator featured an entirely new processor architecture, USB (Mini-B) and IrDA (IrCOMM) infrared communication, memory expansion via an SD (SDSC/MMC) card, and a slightly larger screen, as well as other improvements over the previous model. The calculator system did not run directly on the new ARM processor, but rather on an emulation layer for the older Saturn processors found in previous HP calculators. This allowed the 49g+ to maintain binary-level compatibility with most of the programs written for the HP 49G calculator, as well as source code-level compatibility with many written for the HP 48 series. Despite the emulation, the 49g+ was still much faster than any older model of HP calculator. The speed increase over the HP 49G is around 3-7 times depending on the task. It is even possible to run programs written for the ARM processor thus bypassing the emulation layer completely. A port of the GNU C compiler is also available (see HPGCC below). hp 48gII The hp 48gII (F2226A), which was announced on 20 October 2003, was not a replacement for the HP 48 series as its name suggested. Rather it was a 49g+, also with an ARM processor (unlike the HP 48G), but with reduced memory, no expansion via an SD memory card, lower clock speed, a smaller screen, and a non-flashable firmware. This calculator seems to target users that desire mathematical capability, but have no desire to install many programs. The original 2003 version had 128 KB RAM and ran on 3 AAA batteries, whereas the second 2007 version (based on the Apple V2 platform) needs four AAA batteries and comes with 256 KB RAM, added a USB (Mini-B) port and features a better keyboard. HP 50g The HP 50g (F2229A) is the latest calculator in the 49/50 series. The most apparent change is a revised color scheme, returning the unit to a more traditional HP calculator appearance. Using black plastic for the entire body, white, orange and yellow are used for function shift keys. The back shell is textured more deeply than the 49g+ to provide a more secure grip. A blue and white color scheme variant specifically tailored