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Yes, the 486 or 586 are far more powerful processors than what you would actually need for everything but the cockpit UI. You could probably get away with a Z80
by jschwartzi 8y ago
Yes, the 486 or 586 are far more powerful processors than what you would actually need for everything but the cockpit UI. You could probably get away with a Z80 or something similar. The flight control computers in our space probes frequently have a similar level of functionality simply because it's more than enough.
The only thing a more modern processor buys you is more memory, a faster tick rate for your RTOS, potentially an MMU if it doesn't cause substantial timing skew, and high-precision floating point. In the case of an avionics system I would imagine the requirements for fixed-point arithmetic are very well-understood at this point, so floating point doesn't buy you a whole lot and potentially creates new and exciting problems.
So I would say that 90's-era computers are plenty powerful for what they're used for.
- bluedino 8y agoThe goddamn space shuttle ran on 386's, and that was an upgrade from 8086's
- bdavis__ 8y agoi think the space shuttle used a couple of AP101's, which were 16 bit machines, with core memory, programmed in JOVIAL...
- kakwa_ 8y agoIIRC, the Airbus A320 uses several older CPUs like that, but also Motorola 68k CPUs (sometimes as a mean to have 2 functionally identical systems with pieces from different manufacturers and different implementations). I would not be surprised if they still use 68k in the A320 NEO. Between specification, implementation, validation and testing, the cycles in the aircraft industry can be quite long. 5 to 10 years usually. And it's also quite costly to validate a brand new system. That being said, given the safety requirement, it's for the better.