In October of UC 0081, the Earth Federal Forces launched an ambitious plan to restore their pre-One Year War strength. As part of this reconstruction plan, the Federal Forces began the Gundam Development Project, a top-secret program to create next-generation mobile suits. The lunar manufacturing corporation known as Anaheim Electronics was contracted to develop several prototype designs based on the successful RX-78 Gundam. The first two prototype units were completed at Anaheim's Von Braun factory in September of UC 0083, and on October 7, they were sent to the Federal Forces' Torrington base in Australia for testing under gravity.

The Gundam GP01, code-named "Zephyranthes," is one of the two prototypes sent to Torrington. A general-purpose close combat mobile suit like the original Gundam, it uses a redesigned core block system to increase the survivability of the pilot and combat data. Since the Gundam GP01's main engines and avionics are all part of the core block, it can be adapted for different combat environments by swapping in a different core fighter. However, once configured for one environment, it performs very poorly in others. Aside from the standard head vulcan guns, beam sabers and beam rifle, the GP01 did feature more up-to-date avionics and control systems, as well as a general increase in acceleration and maneuverability.

Source: Gundamproject.com, Gundam 0083 Visual Comic