While the Earth Federal Forces' "Project V" mobile suit development program was underway at the Side 7 research colony, the Federation also began production of experimental units at its Jaburo military headquarters on Earth. Intending to help turn the tide of the ground war during the One Year War, the engineers at Jaburo used spare parts originally manufactured for the RX-78-2 Gundam prototype and built approximately 20 units of a specialized ground combat-model Gundam, the RX-79[G]. In the resource-rich and strategically vital Southeast Asian region, twelve of these units were assigned to the Kojima Batallion stationed in Southeast Asia, particularly to the 04th and 08th MS Teams.

Though in many ways similar to its RX-78-2 predecessor, the RX-79[G] was quite a bit different in other ways, particularly in its armament. Like its namesake, the RX-79 was armored with sturdy Luna Titanium armor, and its powerful reactor enabled it to use beam weapons. However, many internal components were rearranged; the beam sabers were stored in the legs, and the backpack mounted an equipment rack to carry storage containers, parachute packs, or other accessories. The head vulcans were removed, the head now carries a periscope for underwater and trench warfare. The Gundam still had the generator power to use a beam rifle, though it was often equipped with a standard 100 mm machinegun or a heavy 180 mm cannon. Also, a single vulcan gun and a multiple-use "multi-launcher" mounted in the side of the chest rounded out the new armament. The complicated and expensive Core Block System was also omitted for a standard cockpit mounted in the upper chest just below the head.

Source: Gundamproject.com, Mobile Suit Gundam