The Catacombs The Continuity Guide
Technical Facilities
by Martin Willey

Computer Hardware

Thanks to Marcus Lindroos

X5 Computer Panel/Hardware Features

The Year One panels are tagged "X5 Computer" (occasionally seen in Year Two, in Eagle sets and outside Command Centre). There was an X5 Computer on the Uranus mission of 1986 (Death's Other Dominion), so the X5 is at least 13 years old in 1999. Although commercial computers have developed rapidly, computers in aircraft and spacecraft must be "hardened" against vibration, radiation and vacuum. As a consequence, aerospace computers develop much more slowly than business computing.

The X5 bears a striking resemblance to the PDP-11 - a very popular minicomputer in the 1970s/1980s which was designed with mass production and easy maintainability in mind. We might assume the X5 was based on similar commercially available hardware adapted for space use by NASA sometime in the mid-1970s.

The X5 is a highly modular system consisting of wall panels with a standardised size (1x2 ft / 30 x 60cm or a multiple of this) and interfaces. The panels can be easily removed, added and exchanged. The modern equivalent is the rack mounted chassis, which is a 19-inch (48cm) wide single vertical shelf unit, used in modern telecoms and data centres. Like a rack system, specialised X5 compatible panels can be plugged in, including non-computer equipment such as lighting panels, subsystem cooling fans, medical monitors, and a drinks dispenser in Force Of Life.

By simply installing different electronics panels, almost any room on Alpha can serve as a laboratory, medical ward etc. It should also be relatively easy to upgrade the panels once more efficient computing technology becomes available (it is possible that the global war mentioned in The Rules of Luton put an end to these plans).

Death's Other Dominion

In Death's Other Dominion, the Uranus expedition of 1986 has an X5 computer.

Voyager's Return

The same type of panels are seen in the Voyager from 1985 (Voyager's Return).

Dragon's Domain

The Ultra Probe from 1996 has a different type of computer (with quarter inch tape reels from the UFO series which was set in 1980) except for a few panels on the flight console. (Dragon's Domain) so it is possibly an earlier design than the other spacecraft seen in the series.. The Swift, also from 1996, uses more X5-type computer panels (Brain The Brain).

Another Time, Another Place

Close-up of "empty" computer panels, showing the box framework into which the individual panels were fitted. The basic panel was rather wide (1x2 ft.) but not very thick. Note cut power wires. Similar blue, back-lighted empty panels could be seen in the observation room in Breakaway and the Computer Room in Black Sun and Space Brain.

Computer panels

This diagram shows the generic Year 1 computer panels. Minor variations (e.g. panels turned upside down or missing some markings) are not included. Unique avionics panels such as the Earthbound Converter Main Unit, Year 2 Weapons Section or Eagle cockpit wall panels are also not shown.

The Exiles

The Year 2 life support room in The Exiles. The third panel at right (behind Zova's shoulder) is unusual; in Year 1 it only appears in the Force Of Life Nuclear Generating Area.

Another Time, Another Place

In Another Time Another Place, Kano pushes a button in response to Koenig's request for "computer identification", immediately causing a violent short-circuit in the adjacent panel. This type of panel is never used in other episodes, although it is frequently seen in the background

Ring Around The Moon

Many X5 computer panels have removable circuit cards that presumably house computer peripherals etc.. Some can be taken out without removing the front panel.

The Seance Spectre

Some computer panels only house circuit cards, hidden behind a front panel with two handles for easy removal.

Black Sun

The Year 1 Main Power Unit has larger (2x2 ft.) electronic equipment bays.

Force Of Life

The Force Of Life Nuclear Generating Area 3 computer wall features, among other things, a drinks dispenser.

Mass Memory Storage and Transfer

Computer maintains a vast information database. Some of it is related to internal Moonbase data and procedures (e.g. "Directive 4" in The Metamorph, inventory of supplies in The Infernal Machine). There is also an electronic encyclopaedia containing images (The Seance Spectre), ancient languages such as sanskrit (The Testament of Arkadia), sports trivia (Journey To Where), celestial objects and past space missions (Brian The Brain, Ring Around The Moon, Voyager's Return) and undoubtedly countless other topics.

The Bringers Of Wonder part 2

In The Bringers Of Wonder and other episodes, the Alphans apparently use small solid state memory cards for e.g. video camera and audio recordings

The Metamorph

Wall-mounted data cartridges were introduced in Into Infinity and were retained for the Year 2 Weapons Section set as well. The removable cartridges (labelled 0-9) apparently store computer software or data, e.g. cartridges #2 and #4 contain the Altares main computer "navigation codes" in Into Infinity.

Ring Around The Moon establishes that Central Computer has more than 370 "memory cells" for information storage including some which are not available to all users on security grounds (e.g. cell 371 contains the complete breakdown of the Alpha life support system). It is possible to set up memory cells so that key circuits are jammed; the computer needs 32 seconds to 'clear' (reset) each. The term "memory cell" refers to databases (probably in hard disc storage) rather than what is now called main memory, the electronic solid-state random access memory (the jamming sounds like a deadlock between competing resources, a common database problem that has to be fixed by restarting the database).

Some sort of back-up operation ("transferring data to the main computer memory banks") is under-way in Brian The Brain (actually displaying pages from an astronomy text book, including maps of the north pole of Mars), during which the entire memory is wiped. The term "memory bank" here signifies some sort of hard disk storage (more precisely, database storage). The reference to "holographic programming" in Brian The Brain suggests that data is stored optically in crystals or photo-polymers rather than magnetic or optical hard discs.

Communications and Networking

Guardian Of Piri

The standard "diagnostic computer memory link" panel has five ports for data communications cables. The ports look like 25-pin D-sub electrical connectors, such as RS-232 serial ports (introduced in 1962, and standard on PCs until the 2000s). It is used in most Moonbase Alpha areas.

The Alpha Computer system is clearly heavily dependent on networking since X5 computer units are located all over the base. Possibly, the X5's hardware limitations are alleviated by clever software design and distributed computing techniques, with programs running concurrently in parallel on countless X5 units.

Several wall panels feature blinking lights that probably indicate data transfer between computers or mass memory devices. It seems at least some of the power and communications cables are located above the ceiling inside rooms and corridors (War Games, Another Time Another Place). Computer also has wireless "transmitters" for e.g. commlocks; in some episodes (Space Brain, Ring Around The Moon) malevolent aliens give abducted Alphans the ability to communicate telepathically with Computer. Dedicated data transfer panels can be seen in Space Brain and Guardian Of Piri, where David Kano's brain is connected to a diagnostic computer using a data cable.

Copyright Martin Willey
Thanks to Marcus Lindroos