3 ms·
Simple speculation: The software makes heavy use of 80286 protected mode and its quirks, which in an embedded hi-rel environment is fine. An areospace 80386 doe
by datenwolf 7y ago
Simple speculation: The software makes heavy use of 80286 protected mode and its quirks, which in an embedded hi-rel environment is fine. An areospace 80386 doesn't necessarily have higher throughput (remember, these are in-order-execution architectures), if run at the same clockrate. And you probably can't simply increase the clockrate, since some timing may depend on the CPU clock, due to busy-loop waiting, or some sensor readout/communication using the CPU clock for protocol timing.
- NikkiA 7y agoIIRC there were huge swathes of 'gotchas' with running 286 pmode code in 386 pmode, to the point where lots of code simply wouldn't work at all. (One thing that springs to mind was that the way addresses running past the end of a segment worked was different)
- rbanffy 7y agoA batch of CPUs of 286 complexity on a more modern process can't be that high compared to the development of a new aircraft (which the MAX kind of is).