The Supercomputer, also known as the Supercalculator, is a futuristic quantum computer built by Waldo Schaeffer sometime after his defection from Project Carthage, designed to be able to host both the virtual paradise of Lyoko and the multi-agent system designed to destroy Carthage, XANA.

Capable of technological marvels, including time manipulation, possession of living organisms, and the ability to virtualize humans into digital worlds. It is directly linked to the virtual world of Lyoko, which itself is linked to the Supercomputer's abilities through constructs called Towers.

It is hidden in an abandoned factory in Boulogne-Billancourt, France; where it remained dormant for many years until the day when Jeremie Belpois discovered and reactivated it.

History

After his wife, Anthea Schaeffer was kidnapped by the Men in Black due to his defection from Carthage, Waldo took his only child, Aelita Schaeffer with him to France where he changed his name to Franz Hopper by using his middle name and his wife's maiden name to hide his identity. Moving into The Hermitage, Franz (Waldo) got a job at a local boarding school, Kadic Academy as the science teacher for middle and high schoolers while he had Aelita study at home abroad to keep the Men in Black from finding them.

However, knowing that Project Carthage continued on and was a threat to the world, Franz decided to create his own projects in order to counter Carthage. Using the abandoned factory located near Kadic and his home as a place of operations, he secretly built his own supercomputer where he would spend the next seven years programming Lyoko, the virtualization process and most of all, X.A.N.A. in order for the program to destroy Project Carthage.

During the construction of the Supercomputer, Franz Hopper used the Time reversion in order to complete his work on the computer's internal data. Each time reversion doubles the processing power of the Supercomputer, and by extension, X.A.N.A., at least while the program was bound to it.

The Supercomputer is powered by a nuclear battery, specifically, a Uranium rod. The first one, used by Franz Hopper, had a lifespan of about 10 years at most, while the lifespan of the second one is unknown, but can be assumed to have about the same amount.

The actual Supercomputer is at the lowest level of the Factory where it rises from a hatch with some sort of liquid, most likely water that is used for cooling in the center of the room. The Supercomputer also has a monitoring port a few stories above, but only Jeremie and Aelita can fully understand its potential.

In The Girl of the Dreams, Jeremie shouts "Return to the past now!" and a return in time initiates, even though he has been dragged away from the computer. This may mean that the Supercomputer can take voice commands. Later on, during Killer Music, Jeremie programs in a Time Reversion to activate the instant a tower is deactivated, before being incapacitated by X.A.N.A.'s latest attack.

In the second season, X.A.N.A. and Aelita were both dependent to the Supercomputer's survival. Should it have failed, or ran out of energy, X.A.N.A. would have been destroyed along with Aelita. To that regard, the Lyoko Warriors did not shut down the Supercomputer because of Aelita's dependency to the computer. At the end of Season 2, X.A.N.A. managed to obtain the Keys of Lyoko from Aelita and escaped into the network, no longer being restricted to the Supercomputer. Soon afterwards however, Franz Hopper managed to restore Aelita's memories, eliminating her own dependency on the Supercomputer.

Throughout the third and fourth seasons, as X.A.N.A. was freed from the Supercomputer, the multi-agent system launched several attacks on the machine itself in order to permanently destroy the Lyoko Warriors' means of fighting it. These attacks included: direct electrical damage via human possession, destroying the factory itself, or hacking into the maintenance systems.

In the series finale, the group finally shut down the Supercomputer. Also, in this episode, its hatch is seen with the Eye of X.A.N.A. on it.

The Supercomputer would later be reactivated when X.A.N.A. was revealed to have survived its initial destruction. It was discovered that its data had degraded somewhat, with two of Lyoko's sectors gone and the computer interface changing. The Supercomputer would later be deactivated once more after the climax of the Lyoko Warriors' attempt to destroy the Cortex. 

Trivia

• Despite its name, it has been stated that the computer housing Lyoko and X.A.N.A. is actually a quantum computer, making it vastly more powerful than a supercomputer. While a supercomputer is a massive computational system using thousands of processors working simultaneously in tandem, it still uses classical bits (1s and 0s) for computing - while a quantum computer uses qubits instead. Qubits differ from bits due to quantum mechanics allowing the qubits to be either a 1, 0, or both simultaneously - something that is impossible for any other kind of computer, no matter how powerful it is.

• The Supercomputer's design is based off of the original design for a real-life super-computer called Cray-1.
• Franz stated that he "discovered" the return to the past feature after he had built the Supercomputer, making the function an emergent quality.
• The quantum data storage must be extremely volatile. Between Seasons 4 and 5, the data for 2 sectors degraded away. While this suggests the Supercomputer wasn't designed to be offline for a very long time, it is inconsistent because after Aelita was first put in the Supercomputer, the system was offline for 10 years until Jeremie rediscovered it. During that 10 year period, there was no obvious data degradation, aside from the loss of Aelita's memory. It's unknown why it was able to remain stable in storage for 10 years without problems, yet later suffered significant data degradation after only one. There are a few in-universe explanations for this (the true reason being that it was deemed uneconomical by the producers to create all of the sectors for Season 5):
  • It could be because Aelita, X.A.N.A., and Franz were still in the Supercomputer to maintain the integrity of the data.
  • Another possibility is that when Jeremie and Aelita rebuilt the sectors between Final Round and Double Take, they made a mistake that would eventually cause the degradation of the sectors if the Supercomputer went offline.
  • It's also possible that it degraded during the 10 year period, but wasn't noticeable as the only scene of Lyoko before it was shut down was in Aelita's flashbacks of the Forest Sector with Franz Hopper. It is possible that there were more than 5 sectors to start off with and it just degraded from X sectors to 5 to 3 over the years.
  • It could be that Franz didn't shut down the Supercomputer completely.
  • X.A.N.A.'s various attacks on the Supercomputer during the third and fourth seasons (False Lead, Sabotage, and A Lack of Goodwill for instance) eventually caused data degradation while the Supercomputer was offline.
• The fact that the Supercomputer was shut off while Franz Hopper was on Lyoko proves that he can trigger the power switch from inside the virtual world. 
• It is possible the Men in Black would come and dismantle the Supercomputer for their own usage.

Operating system - theory

• Very little is known about the operating system that the Supercomputer runs on, and it is very likely that a custom one was created specifically for it. Based on what the screen looks like in the show, it is theorized that the Supercomputer uses a type of Unix operating system. This is more likely as demonstrated by the fact that Jeremie needs to input a line of coding for nearly every task, similar to how a lot of Unix-based operating systems work.
• The operating system of the Supercomputer is ill-defined, and the kernel of the operating system is a mystery. It is not stated if it's a micro, macro, or exokernel.
• Whenever Aelita used the interface in the Celestial Dome of Sector 5, Jeremie was locked out of the system. This suggests the system is either single-user, or has heavy security features. However X.A.N.A. and Jeremie were able to have towers active at the same time. This suggests the system uses a multi-user capable kernel.
• Despite maintaining Lyoko being such a critical function, the system was able to remain functional even with parts of Lyoko deleted at various points. Therefore maintaining Lyoko is not a core part of the operating system, although it may be a loadable module. This suggests the system is not a macro kernel. Additionally, the towers act as control for the machine's true power. This suggests that part of Lyoko is a set of abstraction layers/drivers for parts of the Supercomputer. Therefore, while it was not stated, it's probable that the quantum computer uses a hybrid kernel with loadable modules.
• Based off what is seen in the cartoon, the Supercomputer may be a computer that runs an exokernel that ships packets of data to other various electronics. These packets of data can range from a micro kernel of the Supercomputer's main kernel to drivers that alternate the purpose of the device. This is semi-supported by X.A.N.A.'s ability to make electronics malfunction and even give them sub-human abilities.

Gallery

Prequel and Seasons 1-4

Evolution

v · d · e Lyoko
Characters	Franz Hopper X.A.N.A. Lyoko Warriors Jeremie Belpois Aelita Schaeffer Odd Della Robbia Ulrich Stern Yumi Ishiyama William Dunbar
Locations	Sectors Ice Sector Desert Sector Forest Sector Mountain Sector Sector Five Arena Celestial Dome Core Zone Data Tunnels Skidbladnir Hangar Heart of Lyoko Other Digital Sea Virtual Limbo
Hardware	Factory Interface Holomap Scanner Supercomputer
Virtual Objects	Eye Scanner Lyoko Wires MegaPod Overboard Overbike Overwing Skidbladnir Nav Skid Tower Way Towers Transport Orb Virtual World Shell
Programs	Annex Program Anti-X.A.N.A. Program Avatar Codes Lyoko Earth X.A.N.A. Scipio Deletion Devirtualization Digital Genetic Code Energize ID Card Keys to Lyoko Life Point Memory fragment Pulsations Sector Alteration Program Simulation Bubble Superscan Telephone Vehicle Virtualization Program
Weapons	Lyoko Warriors Katana Laser Arrow Tessen Fans Zweihänder Monsters Circular Laser Flying Mine Hallucinogenic Beam Laser Pulse Beam
Powers	Catclimb Energy Beam Energy Fields Enhanced Marksmanship Feline Execution Monster Riding Second Sight Second View Shield Super Smoke Super Sprint Telekinesis Teleportation
Other	Eye of X.A.N.A. Gunship Virtual Weather