Mainframe
| Kind | Fascia of the Citadel |
|---|---|
| Also called | The box, the surface |
| Size | About 20,000 km long and wide, 10,000 km high |
| Strata | Land, Thermoconductor, Circuit |
| Largest city | Ganden |
| Main currency | ORE |
| Population | Hundreds of millions to billions (estimates) |
Mainframe is humanity's primary known world: a disputed fascia somewhere in the middle layers of the Citadel and probably one of its computational hubs. Its inhabitants also call it the box or the surface, and most believe its walls mark the edge of existence.
Geography
The known volume is continent-like—roughly twenty thousand kilometers in length and width and ten thousand in height. Its outer walls are made from an unknown material that has resisted mechanical attack, thermal cutting, and significant-yield nuclear detonations.
Mainframe is not a planet. Its geography is a technogenic landscape of corridors, tunnels, pipes, docks, gates, pressure systems, reservoirs, moving components, circuit arrays, and chambers large enough to contain atmosphere, water networks, vegetation, and terrain that appears natural.
It has artificial gravity and breathable air below roughly two thousand meters. Temperatures remain between about five and thirty degrees through much of the inhabited volume, then fall sharply with altitude as water freezes and the atmosphere thins. The central zones hold most settlements; the distant reaches are sparse, hostile, and poorly mapped.
Strata
Three strata define the known world. Land is the upper and most spacious, filled with open chambers and bio-greenhouses. It contains Zion—the safest inhabited region—and cities including Ganden, Bastion Serat, Acheron, Heraclea, and Sinop. Tzhal, the old center of TZHAL civilization, lies in a distant part of the same stratum.
Thermoconductor lies beneath Land. It is a dense network of shafts, air ducts, heat exchangers, and thermal conduits, with major settlements such as Culminar's Forge and Thermopolis built around industrial flows that long predate them.
Circuit is the third, deepest, and darkest stratum. It is the least explored part of Mainframe and sits directly above the Bottom. Porto Tessera, one of humanity's major scientific and technical centers, survives there close to routes most crews refuse to enter.
Beyond the walls
Mainframe may be only one fascia inside a much larger structure. Unstable corridors beneath the Bottom lead toward Void and other fascias grouped by researchers into the Pillar Eucumene, which contains at least sixteen known strata. Some scholars suspect there are multiple pillars and lateral routes, but no reliable passage through Mainframe's outer walls is known.
Peoples and languages
After the Derailment, automatic education and safer infrastructure preserved interface languages and technical fragments in the center. Remote populations without those systems fell into survival cultures. TZHAL emerged from a different language continuum, while the heavily augmented teks abandoned spoken interfaces for direct network protocols and cryptographic script.
Population estimates range from hundreds of millions to billions. Interface languages dominate the central zones, TZHAL may have one to two hundred million speakers, and millions of teks remain difficult to count because their clans are closed, scattered, and often nomadic.
History
Ship acquiring changed the scale of history. Ships made long trade routes, distant colonies, large migrations, and regular communication possible. Tek caravans crossed enormous distances, merchant fortunes grew, pirates gained new ranges, and armed helmsmen converted transport power into feudal protection.
Warship ownership reorganized society. Producing households sought protection from helmsmen and kanoniers; navs and fleetmen formed a shipborne aristocracy. In the cities, guilds, manufacturers, merchants, and logistics companies competed to control goods, routes, storage, and armed delivery.
The Old War began in 966 AI when the expanding THALIT Union invaded the central city-states. The Communal League failed, defecting lords joined the TZHAL fleet, and THALIT ruled much of Mainframe for centuries. Resistance survived through schism, crusades, periodic reconquests, and the fortified independence of orders such as Ordo Crucis.
THALIT fell during the Credit Revolution of 1510 AI. Ganden seized the richest routes and institutions while surviving commanders formed the TZHAL Emergency Government. Their unfinished war now divides Mainframe alongside city-states, monasteries, fleet domains, manufacturers, logists, tek clans, pirates, and communities too distant to recognize either claimant.
See also the Timeline.
Law
Raw force remains the final guarantee of property. Ganden and TZHAL publish formal law, but an older unwritten system—lock law—governs ships, docks, gates, mooring, freight, dues, and vassalage. Even pirates often obey it because every captain depends on the same passages staying usable.
Economy
ORE issued by Ganden is the dominant currency. TZHAL circulates its own depreciated ORE; heap provides a notional unit for barter in useful junk; Ordo Crucis retains the ancient licent. Mainframe's three principal producing industries are manufacturing, raking, and breaching, supported by logists who transport, guard, store, or seize cargo.
Ships are transport, homes, communication relays, industrial tools, weapons, and objects of worship. Fusion fuel from deuterium and helium-3 is supplied through ancient fuel wells. Power comes from ships and thermal, induction, or charging farms attached to surviving Citadel systems.
Frontier
The frontier contains feral husks, ghouls, morning stars, hostile daemons, wire wraiths, security systems, aberrations, radiation, magnetic fields, moving machinery, traps, pirates, coloners, and isolated tribes. Distance from the inhabited center is measured not only in kilometers, but in how little anyone can confirm about what waits there.