Jacqui wrote There are several possible reasons for the 'tarriel cell compatible technology' of Zen/the Liberator/the System (Orac has 'no apparent problem' in overriding System computers).

a) Independent but parallel development sufficient for Orac to understand. Going by 20th/21st century computers this is 'unlikely.'

David There have been several lines in 20th cent. software systems, but now there are few: the minority systems of Apple and Unix; the majority system. It can be the same for B7 hardware. Initially there were several lines but most died out leaving a few only: Tarriel cells, Star One, the System, the Ultra's technology. There is only so much that can be invented in a given area; then the variations merge.

Jacqui This implies some communication between the System and the Federation - probably one way as even Servalan/the Federation High Command are unaware of the System.

David The previous generation, however, were not necessarily unaware of the System. When Control was placed on Star One, someone somewhere knew the fact. Then the knowledge concerning the location of Central Control died out. Likewise, the knowledge of the System could have died out by the time Servalan assumed power.

Jacqui This would also imply that the System is 'not in the direction of' Andromeda/Horizon, or the Federation would have come into contact with it.

David I agree with that.

As an aside I consider Earth, Horizon, Star One, Andromeda to be in a straight line. Earth is in Earth Sector (Zero), but the other three are in Sector Eleven. From Horizon we see that zone nine is further out than zone eight. Perhaps Earth is in zone zero, Horizon is in zone 9, Star One in zone 17 ("C 17 320 in the 11th Sect."), and M31 the Galaxy, is in Zone 1,000.

Jacqui Correlating the information in 'Orac' and 'Redemption' the System's space centre was probably constructed long before Ensor developed the Tarriel cells.

David Yes, long before. The complex was around since before the slave's father was born.

Jacqui b) The System goes technology hunting (the equivalent of the Chengas?) - the Liberator/DSV2 is one of a series of such ships, but went close to the battlefield to acquire 'equipment' and got caught in the crossfire.

David The System was born from war, from its latter stages

Slave: The three planets were always fighting or getting ready to fight. Then one of the planets developed a computer so powerful it was able to take over the weaponry computers of the other two: One gigantic System that totally governs the three worlds. Blake: And the System built this as a control centre? Slave: Yes, now there is no war.

There were three worlds and a central system. This is similar to the design of the Liberator: a middle hull, surrounded by three lesser hulls. There is an earlier mention of a long war: Duel. Emigrees of Sinofar's and Giroc's race or races from their thousand years war may have had something to do with these things.

Except for Keezarn (City), no-one else has teleport, not even Dorian. It seems likely the System is at the cutting edge of technology.

Perhaps Zen deliberately hunted for a war to involve himself in. Perhaps he shunned war and attempted to keep out of it.

Jacqui c) My previous suggestion that Ensor came from the System, bringing the tarriel cell technology to the Federation. (This might explain why he did not have his mechanical heart replaced - incompatible tissue types.)

David It is an appealing idea. He is similar to the slave, and both are seemingly human. I am beginning to like it more and more. He could have brought Avon (See below more about his possible second son).

Jacqui d) Ensor (who, it appears withdrew from the Federation so he could get on with his researches privately) encountered an earlier System spaceship with 'tarriel cell equivalent technology' and made use of its technology. Neither this nor c) reflects against Ensor's capacities in making the two systems compatible.

David If true, then Ensor is not the inventor of the Tarriel cell. That takes away some of the emotion when he dies, and when his son dies in an earlier episode. Ensor's distaste for drugs ("I can't stand them, myself. Filthy things, drugs") and guns suggests some disagreement between him and his Federation Overlords.

Jacqui Any other possibilities?

David Muller? Dorian? The Ultra? These are not necessarily probable, though. Further-fetched include: Ancient Keezarn? Auron? Emigrees from Sinofar's race?

Jacqui As for Avon - when would he have come from the System (and why?)

(snipped late appearance in Federation untenable)

If he was a former inhabitant of the system he probably moved as a child (which, if he was 'mechanically gifted' would still enable him to have some idea of the technology he left behind).

David Hal Mellanby made a deal with the Federation that allowed him to take Dayna. He adopted Lauren afterwards. Was he trying to replace a second child? If so, was that child left behind on Earth?

Is there any possibility the image of Avon's brother in Time Squad was that of Ensor Jr? Ensor Jr. was four years old about forty years ago. He left with his father. Avon is aged, some say, in the early forties. Could he have been an other son of Ensor Sr? If so, was he left behind on Aristo, Zerok, Earth?

Jacqui He could also have a strong visual memory - and there is a #very# noticable constellation in the bit of the System's sky we are shown.

David It looks to me a little like the tail in Scorpio, which, unfortunately, is some distance from Cygnus, and therefore also from the point midway between Cygnus Alpha and Earth.

Jacqui It would be ironic if Avon came from a family which left the System because they disagreed with it, and got caught up in an attempt to overthrow the Federation.

David Given Avon's good and bad luck, maybe it is only to be expected.

DC