[cctalk] Re: Scada computers and remote terminal units

On 25/07/2025 16:05, Jon Elson via cctalk wrote: 5 or so years back there was someone selling Ferranti Argus boards on eBay. They weren't cheap, but I'm kind of kicking myself that I didn't pick up at least one or two. I enquired as to whether he had a card frame and other parts for a complete system and he did for his own testing purposes, but not for sale. He claimed he still had customers running Argus systems for industrial control. I've since learned that up until quite recently there were UK nuclear power stations running Argus 500 based control systems. When I worked for British Gas in the early 90s we had an in-house developed TMS9900-based telemetry outstation, which was used to manage remote gas and radio sites — we had our own national microwave networks and PMR radio etc. — and this would also relay intruder, fire and UPS etc. alarms. Outstations connected back to the main SCADA system via a UHF radio and little yagi antenna pointing at the nearest radio site (if not located at one). It's crazy to think now that this would have been a simple protocol, with no security, controlling valves on HP gas lines, huge compressors, big boilers (to heat pressure reduction equipment to prevent it freezing) and all manner of critical infrastructure. The SCADA system was based on a VAXserver 3800 cluster, with VAXstation 2000 satellite nodes equipped with 21" displays for the 24/7 grid control team. IIRC the SCADA system was developed by Logica. We had a contract with DEC whereby we'd have a full stock of parts and swap out boards and drives etc. The previous system was a Cossor 9900-based mini with Pertec drives and this languished in a corner of the workshop. I'm not sure if this influenced the telemetry outstation CPU choice, as that would have been developed around the same time. I can't imagine there were many sites running Cossor minis, but IIRC Heathrow Airport in London had a 9900-based air traffic control system from them. The previous to that — and very first — grid control computer was also sitting in a garage building. This was an Elliott system and I couldn't say what model (I was more interested in electronics and radio at the time). Sad to say that this and the Cossor were sold for scrap. Another curio from that time was a simple device called, I think, a "radac". This was a magnetic drum audio recorder and tracks would be recorded with the site name and alarm messages. On being triggered it would autodial a number which would be routed to whoever was on call, who would then be greeted by this slightly robotic sounding message. There were still one or two in use at simpler sites. I've since not managed to find any information on this, but have wondered if one could be found, if it might lend itself to being adapted for use as a very small drum store. Andrew