A short high level overview of the initial SMFs NC3 system - Signal A thread. Please feel free to ask questions in comments below. 1/17
First of all some background SMFs became an independent service in 1959 and quickly realized that it was hard to timely and properly C&C it's geographically dispersed forces, particularly with the massed deployment of 2nd gen missile complexes in stand alone silos. 2/17
The central combat control means that were in use at this point were viewed as inadequate, as not sufficiently quick and reliable, particularly under the LoW Yarunuch, a SMFs and GS veteran describes this notion in his book, but you can see the same in other accounts. 3/17
After SMFs got their affairs in order and new CCP operational this lead to a desire to develop and deploy an automated NC2 system in place of the EAM-like Monolith. The system was intended to follow existing hierarchical SMFs structure, with links supporting specific CPs. 4/17
As such it would act as unified finite state machine, with inputs of one link leading to outputs of another, ie order inputted into a high level link (say at SMFs CCP) would lead to pre-determined output (ie indication light) in a lower level link (say a regimental CP) 5/17
The same of course would work in reverse, an input of the lower link (ie a readiness report) would lead to an output of the higher link (ie indication of unit readiness) This lead to the higher links being more complex. 6/17
Such state changes would propagate via formalized messages, which would include address, encoded output state for the intended recipient (link), service information (regarding time, com channel state, etc) 7/17
Each link would follow a similar internal structure - IO/UI, clock, printer, logic, memory, communications equipment. Logic unit would handle a number of tasks, such as encoding/decoding, transforming received messages into output or input into transmitted messages. 8/17
This logic would be built out of logic gates with ferrite-ferrite modules or in other words was entirely hardwire in literal sense. There was also a built in UPS. It would also limit the system to a fairly small number of orders and reports that could be used within it. 9/17
On the other hand when compared to ferrite/transistor modules or general purpose computers it did allow greater reliability and robustness, which was praised both during development and in service. 10/17
In terms of communications the system followed the hierarchical structure of the service, with the links connected to their subordinates and superiors via direct links, typically telegraph over phone lines, with phones lines often rented out by the service. 11/17
This would mean that formalized messages would use links as routing points, should the state change of the system need to propagate more than one level up or down. 12/17
There would also be a built in interface/integration with the RT-2 weapons system, due to it's NC3 component sharing the developer with the SMFs NC3 system, as such inputs into high level links could lead to state change of the weapon system - ie launch. 13/17
Due to the success of this integration and RT-2 NC3 component more generally this set up propagated to other systems, becoming common on the next, 3rd, generation of weapon systems. 14/17
It was also later supplemented by the doubling tract - Vuyga system, where the state change could propagate from high level Vuyga link ("emitter") to any/all (depending on addressing) lower links ("receivers") and via the interface - main tract (Signal) links. 15/17
Vuyga however introduced it's own number of challenges - such as the need to not only organically encode/decode (ie with self correcting codes) messages, but to also encrypt/decrypt them, due to the less consistent, more exposed nature of it's channels (SW/VLF/SatComs). 16/17
Of course there was later supplementary decision making support tools and other additions, but the choice to use rigid ferrite-ferrite module logic did lead to problems down the road, when a next gen Signal-A switched to using general purpose compute to allow flexibility. 17/17
p.s. This was the state of the SMFs NC3 system as of mid 1970s more or less. Later would come integration into the unlocker system, AF's NC3 system (of systems), with the SMF's ICT system and so on. Maybe more on this at a later time.
CC @thedeadhandbook @M51_4ever @OKB1917 @dtc94133 I hope this can act as a pallet cleanser to all the Iran/Israel content :)