Can anyone identify this keyboard?

[themindrobber]

Hi there,

I'm sorry if this is the wrong place to post but I'm hoping someone can help me identify the hardware seen below (fitting into an unrelated green casing) - image taken circa late 1980.

I would also be grateful if someone could enlighten me as to the meaning of the secondary set of characters above the normal QWERTY characters. I've seen them elsewhere but don't understand their significance.

Many thanks if you can help!
Gav

[Starius]

Looks like a prop from something out of Blake's 7 or Doctor Who, or some other sci-fi show out of the late 70s / early 80s.  (The lighting of the scene definitely looks like it was from that era of tv studio production.)
Where did you find it? 

[Coreda]

A Doctor Who prop it seems. Here's a thread discussing the possible base keyboard used and where the keycaps may have been sourced from.

From that topic it appears to be a Honeywell data conversion keyboard that had parts cut from the top and right (edit: looking again it's probably just due to the replacement keys extending over the white key area) and using replacement keycaps.

[Starius]

Oh cool, it was used in Logopolis.  That was Tom Baker's final story. 

[themindrobber]

Thanks very much for pointing me to the other thread. I knew the television source material, it was the hardware I was specifically interested in. Much appreciated.