History of the Telstra Research Laboratories
You have a footnote on your website mentioning
that some TRL staff worked on secret projects to do with national security. In
the 1970's there were rumours floating about the wider Telecom about some
military / national security projects going on, some quite significant
apparently. I recall one rumour that some TRL boffins were trying to work out
(without any success) how to decrypt military comms traffic of a certain
significant foreign country.
In 1980, while the regular chap was on long service leave, and his normal understudy had some extended sick leave, I found myself acting OIC of Telegraphs and Data Base Repair. This section repaired anything that received, sent, or processed text or data - modems, teleprinters, telex machines, VDU's etc. Some of the techs were ex-army & ex-navy. At that time, if an army or navy chap had a health issue that precluded military service, the government would assist him with getting a job in Telecom (or possibly other Govt departments) For instance, one chap we had, was an army signals mechanic and was diagnosed with a serious heart valve defect. The Army paid to have his valve replaced with that of a pig, but that meant he had to be on drugs and have a blood test every 2 days for the rest of his life - that would be no good in the field during a war. But he could work as hard as anybody.
Sometime in the early 1970's or perhaps late 1960's, TRL had developed, and manufactured a number of, certain devices (Here I'll call them C-Units) intended to enable the Army to have more secure teleprinter communications. The C-Box plugged into the network, radio link, or whatever, and the teleprinter plugged into the C-box. They came in a distinctive large custom fibreglass box/crate. When they went faulty, the Army delivered them to us at Base Repair. We had set aside a special room, a lockable disused office in a quiet out of the way part of the building, for fixing them. Incidentally, at points in the circuit where an optocoupler would be clearly appropriate, C-Units had optocouplers. As they were designed before optocouplers were commercially available, the C-Units had optocouplers apparently made in-house by TRL!
One time in 1980, I had a new tech, just transferred from Army Signals. I put him to work fixing modems, which meant he was working alongside me and another tech called Theo. Theo was also ex Army signals but had been in Telecom 20 years or more. After a week or so, the new guy said to me "Where's Theo? Haven't seen him all day."
I said "Theo's up in the C-Room fixing a C-Unit"
"Theo's up in the C-Room fixing a C-Unit." I then described a C-Unit, and where it came from. New chap then had a curious expression on his face, sort of surprised and cross at the same time.
So, I said, "Come with me." And I took him down the corridor. When we got to the room, we could see, through the glass panels in the partitions, Theo, with the fibreglass crate at one side, C-Unit innards strewn about on a table, and the circuit, a typical Telecom Drafting product on a dirty great A0-size sheet, taped up on a wall. The new chap just looked with his mouth open. After a moment, Theo noticed us, and opened the door, saying "Did you want to talk, Alan? Come in."
I replied, "Nah, Theo, I'm just showing the new lad around." And took said new lad back to our main work area, he muttering all the while "They are restricted, secret. That room is not secure....."
I said "I suppose you're right. But we use common sense here. Much better devices that are not obsolete are used by the banks anyway." In any case, knowing the circuit will not enable breaking the cipher.