A Mobile Suit frame produced around 300 years ago during the late stages of the Calamity War by Gjallarhorn. Mobile Suits using this frame played a major role in the war, and were also said to have been involved in several flash points throughout history that led to important outcomes for humanity. These machines were each given a name of one of the demons of the Ars Goetia.
The Gundam Frame is able to achieve high levels of energy output by using two Ahab Reactors. In fact, the energy output from the two reactors is in excess of which is needed to power the Mobile Suit. The purpose of this excessive output is to ensure a burst of power during the few opportunities available to land a clean hit on the Mobile Armors, the main enemies during the Calamity War. To maximize these opportunities to deal a lethal blow, the amount of energy instantaneously transferred to the Mobile Suit's weapon must be as large as possible. However, because it is difficult to run the two reactors in parallel, only 72 units of these Gundam Frames were ever produced. In addition, the Alaya-Vijnana System is needed in order to make use of the full potential of the twin Ahab Reactor output. For this reason, the Gundam Frames were made to be humanoid as to deepen the link between the Alaya-Vijnana System and the pilot's own senses.
The Gundam Frame is very versatile and can operate in any environment as long as the external parts it is equipped with does not disallow it. It is also possible to use the external parts from one Gundam Frame-specific design to modify another Gundam Frame in a relatively short amount of time. Inside each Gundam Frames, there is an output limiter, which when deactivated allows the machine to go full throttle. There is also a system that activates when the Gundam Frame is in close proximity to a Mobile Armor. It restricts the amount of data feeding back to the pilot via the Alaya-Vijnana system, and is a safety feature to protect the pilot from being overloaded with data which could cause severe damage. This safety feature can cause the Gundam Frame to deactivate or not respond to command when the output limiter is also deactivated. This problem can be solved if the Gundam Frame's pilot switch off the safety feature, exposing themselves to the risk.
Currently, it is impossible to reproduce the Gundam Frames with modern day technology, and they were hard to make even during the Calamity War era. As of P.D 323, 26 Gundams are confirmed to still be in existence, and are in different situations. It is known that the Gjallarhorns' Seven Stars used the Gundam Frames during the Calamity War, and these machines are still in their possession in the current age.
Produced at the end of the Calamity War, the Valkyrja Frame was shaped to be lightweight and mobile, and compared to the other Calamity War era machines, its design is simple with minimal energy loss. It is also designed to be adaptable to suit its equipped armaments. Although it has only one Ahab Reactor, its frame design allows it to realize performance second to that of the Gundam Frame. With its specifications, the Valkyrja Frame had the capabilities to be the main combat machine on the battlefield. However, as it was developed at around the same time as the Gundam Frame, not many people were aware of its existence.
The remaining data from the Calamity War era suggested that the overall production number for Valkyrja Frame-based mobile suits was small, only about nine machines, and there was not much information regarding their combat record. After the Calamity War, with the requirements of a Mobile Suit shifting to balance and efficiency, the performance of the Valkyrja Frame was reexamined and Gjallarhorn decided to use the frame as the base for their mobile suit development, resulting in the Geirail Frame and later, the Graze Frame.
A general purpose MS frame developed by Gjallarhorn. The Geirail Frame is a downsized, mass production version of the Valkyrja Frame which has high performance but hard to mass produce.  It served as the predecessor of the Graze Frame. There are many commonalities between the Geirail Frame and the Graze Frame, such as basic control system and structure, but there are also differences in the arms, legs and other minor areas. This is due to maturation and optimization of the design as time passed. Although an older generation frame, its Ahab reactor output is stable and movements are fine.
The Graze Frame was one of the first Mobile Suit Frame developed after the Calamity war, it was based on the Geirail Frame and can trace its roots back to the Valkyrja Frame. A design that had matured through 300 years of post Calamity War development. It was carefully designed for general purpose use, and through exchanging armaments and armor, it can adapt to various environments as well as use various loadouts to meet the needs of different mission.
The frame was also created to be lighter and simpler; compared to the Gundam Frame that represents Calamity War era MS, the Graze Frame is made using much lesser structural material. This also made the frame easy to maintain. Other characteristics included high producibility, excellent operability, and energy efficiency. Its Head Sphere Sensor is usually concealed behind armor but can be revealed when needed, and this concept is inherited from the Grimgerde's High Sensitivity Sensor. The frame itself had variants for different characteristics.
Successor to the Graze Frame, its development was motivated by the appearance of powerful, armed civilian groups like the Tekkadan. It inherited the beneficial characteristics of the Graze Frame such as ease of maintenance, simplified structure, and high versatility, and was made to be better at anti-MS battle. Some of these improvements for anti-MS combat include better sensors, joints with a higher degree of freedom (i.e. ball-shaped joints for joint parts such as the shoulders and thighs that require large torque) and the ability to handle heavier armament. Compared to the Graze Frame, the Reginlaze Frame's structure have a higher level of resemblance to the Valkyrja Frame. Its concealed head sensor have three cameras instead of the Graze Frame's single camera.
The Rodi Frame was one of the many frame types produced during the Calamity War. Many mobile suits using this frame were mass produced during the middle period of the Calamity War, and served as the main units in the Outer Sphere for many years. As the Rodi Frame does not have a defining characteristic feature, it also does not have many drawbacks either and is thus considered to be very versatile. Due to its versatility, it is often equipped with heavy armor. Rodi Frame-based machines are now common among civilian hands, with unqiue customized units being use by mercenaries, space pirates, etc. Some of these machines are illegally fitted with the Alaya-Vijnana system. Used parts and customization parts for the Rodi Frame are widely circulated.
The Teiwaz Frame is the first non-Gjallarhorn MS frame completed in recent years, and is developed by Teiwaz to counter the threat posed by pirates on its trade routes. The frame was developed by Teiwaz's engineers based on the blueprints of a high output machine that was planned to be developed during the late stages of the Calamity War. Unlike the Mobile Suit Frames used by Gjallarhorn, the Teiwaz Frame's Ahab Reactor is from ancient times. This is partly due to the fact that Gjallarhorn has a monopoly on Ahab Reactor technology in the present day. Development of the Teiwaz Frame was difficult and took a long time, evidence of this is that the mass production line is not ready yet in P.D. 323.
The Io frame is the mass produced mobile suit frame created using the technology accumulated from the development of the Teiwaz Frame. Teiwaz developed it with the intention of selling it as a product to other factions in the future. Although designed from scratch, it shares the same design philosophy as the Teiwaz Frame. As a result, its structure follows that of the Teiwaz Frame and there is no change in external appearance (even the cockpit area is the same as the one employed by Teiwaz Frame), but minor parts such as the drive components are adjusted for mass productions. Thus, the two appear to be sister machines even to great technicians. Like the Teiwaz Frame, it uses Ahab Reactor from ancient times. This versatile frame has multiple high sensitivity sensors in the head, and can be equipped for different environment.
After the Rodi Frame, Hexa Frame is the second most produced mobile suit frame during the Calamity War. A characteristic of the Hexa Frame is its lightweight, as it is designed to sacrifice defensive capabilities for high mobility, making it the opposite of the Rodi Frame which tend to be equipped with heavy armor. This however caused it to be less bullet resistant than other MS frame, and many Hexa Frame-based machines were shot down during the Calamity War. To compensate for its weakness, Hexa Frame-based machines primarily operate in groups, and in support functions in the mid-close range.
Due to the location of its Ahab Reactor, many Hexa Frame-based machines do not have chest-mounted cockpit. Instead their cockpit block is located in the head, backpack, or other high areas. Due to this, their pilots have an easier time to bailout, and thus a higher pilot survival rate when compared to other mobile suit frames. There are also many Hexa Frame-based machines with changes and augmentations to the frame’s range of motions such as the Hugo, which has reverse-jointed legs that can function as arms. Although there are less surviving units than the Rodi Frame, the amount left is still considerable. Users of the surviving Hexa Frame machines include civilian security companies, space pirates and pilots that prefer machine with high mobility.