The Cyber-Mainframe, referred to by the Machine as the Hive, was the Cyber-network utilised by a race of Cybermen, native to a parallel universe, that sought to upgrade the entire multiverse in a campaign dubbed "the Cyber-Ideal".
The Cyber-Mainframe was a significantly large Cyber-network, as it linked Cybermen, Cyber-Technology and other Cyber-units across separate parallel universes and alternate timelines. (AUDIO: Code Silver) Cybermen and other cyber-converted lifeforms were automatically connected to the Mainframe once they were upgraded (AUDIO: Code Silver, Telepresence) - with the exception of a group of Cybermen converted via a signal emitter possessed by the War Master (AUDIO: Master of Worlds) - and lifeforms upgraded by the Machine would be greeted by it to the Cyber-Mainframe with the phrase "Welcome to the Hive." (AUDIO: Telepresence) Once connected, Cyber-units could download updates from the Cyber-Mainframe, with various different purposes; for example, individual Cybermen and mobile conversion units could receive updates containing details on the location of a priority target, or an individual lifeform's specific biological information, thereby allowing Cyber-units to track said individual. In addition, individual Cybermen could download and install upgrades to their offensive and defensive systems, such as a laser cutter setting for their Cyber wrist blasters, and an update to their shields protecting them against potentially harmful types of radiation.
Cyber-Controllers connected to the Cyber-Mainframe were able to broadcast emergency updates to Cyber-units; these units would receive an update alert before downloading and installing an emergency update into their systems. (AUDIO: Code Silver) Cyber-Controllers could also broadcast energy upgrades to, at least, all of the Cyber-units on the same planet as it that were connected to the Cyber-Mainframe at that time. (AUDIO: Master of Worlds)
Virtually-converted humans were also connected to the Cyber-Mainframe upon conversion; although this conversion process rendered the human emotionless, virtually-converted humans who experienced a cranial upgrade had a stronger connection to the Mainframe that allowed them to retain their emotions and original personality, so that they could be utilised in conjunction with their own knowledge and the information already in the Mainframe. This tactic was often used by the Cybermen to assist in the initial stage of dimension seeding: securing a foothold in a new universe reached via dimension bridge technology.
Another significant function of the Cyber-Mainframe was its use as a wireless connection between the numerous Cyber-units and pieces of Cyber-Technology connected to it, and the energy sources that were needed to power said units and technology. Individual Cybermen received this energy via the side handles on their Cyber-helmets. (AUDIO: Code Silver)
Cybermen connected to the Cyber-Mainframe could have said connections severed by electromagnetic interference. This could happen to individual Cybermen through a hoop of cable being hung over a Cyberman's Cyber-helmet, (AUDIO: Code Silver) while a beam emitter used by the War Master was capable of severing the Mainframe connections of a small group of Cybermen simultaneously after approximately ten seconds of use. A significantly large circuit of cables could severe the Mainframe connections of dozens of Cybermen at once if said circuit was connected and activated around all of the Cybermen at once. (AUDIO: Master of Worlds) However, the self-repair systems of these Cybermen would allow them to reconnect to the Cyber-Mainframe after only a few minutes, (AUDIO: Code Silver, Master of Worlds) and Cyber-Controllers could also activate a secondary signal antenna from their chest power cell to swiftly re-establish a connection to the Cyber-Mainframe if their primary connection was interrupted. (AUDIO: Code Silver)
In addition, virtually-converted humans who were connected to the Cyber-Mainframe via a cranial upgrade would experience excessive mental stimulation and, if not fully converted after a certain amount of time, death, as the sheer amount of information contained within the Mainframe was too much for the human brain to properly process. (AUDIO: Code Silver) However, the pain caused by this extreme metal stimulation could be cured by an emergency update from the various Cyber-Controls from all the numerous realities that the Cybermen had established footholds in, although this was only done if the virtually-converted human was necessary to deal with a sudden change in the initial dimension seeding of a new universe. An alternative cure for this extreme mental stimulation was a corrosion virus, which would outright reverse the human's virtual conversion by consuming their upgrades. Virtually-converted humans who had not received a cranial upgrade did not experience this excessive mental stimulation. The humans who were virtually converted by the smartphone app C-Control could have their conversions completely reversed if the app was broadcast to each of them worldwide with its conversion functions reversed. (AUDIO: Master of Worlds)
The Cyber-Mainframe was developed and utilised by a race of Cybermen that originated from an alternate universe. In their operation to upgrade the entire multiverse, these Cybermen used the Cyber-Mainframe to share information and upgrades with each other across the numerous parallel universes and alternate timelines that they invaded, in addition to receiving energy from the numerous locations that the Cybermen conquered. (AUDIO: Code Silver)
At one point in their conquests, the Cybermen successfully invaded a parallel Earth resembling that of the N-Space Earth during the 2010s and enslaved its human population as batteries, harvesting the electricity generated by their bodies and transferring it through the Cyber-Mainframe to assist in powering the Cyber-units and Cyber-Technology connected to the Mainframe. (AUDIO: Telepresence, Code Silver) Sometime after the invasion, when the Petronella Osgood, Vikram Shindi and Josh Carter of N-Space visited this parallel Earth via the use of dimension bridge technology, the Machine used an enormous Mechanising Worm to convert a mutated wild dog, thereby connecting it to the Cyber-Mainframe, although the dog was killed by Shindi shortly afterwards. (AUDIO: Telepresence)
Later, following the arrival of Hive Section 49 at the N-Space Fortress Island from said parallel Earth, the virtually-converted Osgood was connected to the Cyber-Mainframe via a cranial upgrade performed by the Hive Section's Cyber-Controller, who identified Osgood's status as a scientist to be a "useful" skill in the Cybermen's initial dimension seeding of N-Space. While Osgood and the Cyber-Controller worked together to take control of Fortress Island and modify a virtual-reality game created from dimension bridge technology by the Auctioneers to virtually-convert millions of humans across the N-Space Earth, Osgood experienced excessive mental stimulation due to her connection to the Cyber-Mainframe, although she repeatedly insisted to the Cyber-Controller that she should not be fully upgraded until she had completed the modifications to the Auctioneers' virtual-reality game. During the Cybermen's conquest of Fortress Island, 29% of the humans on the base were upgraded and connected to the Mainframe, and millions of humans across Earth were connected to the Mainframe after being virtually-converted by the Auctioneers' modified virtual-reality game. (AUDIO: Code Silver)