Senosa Directdata 640

[Simon Webb]

I've been asked if I can find any information on the following, can 
anybody help?

'We acquired a number of years ago a Senosa Limited Directdata 640
Transmission Processor with Digico Teletype from a local company but it 
came with no information. Could you please point me in the right direction 
for some information about how these items work, date of production etc.'

Simon Webb
Curator, Museum of Computing
www.museum-of-computing.org.uk
Tel: 07939 582544