Re: Hardware capacity
IIRC, the 737 computers use the old 80286 Intel processor. (Ah, those were the days; you could still access the I/O ports directly.) It is easy to see how adding extra tasks for each new 737 variant could lead to situation where interrupt requests (sensor failure, for example) are coming in more quickly than the processor can execute the Interrupt Service Routines. The growing stack will eventually overwrite the code. This could easily lead to "blips" like those observed in the FDR traces, where the pilot presses the yoke trim switch but nothing happens. Not enough harware capacity.
YYZjim