I'm not sure what I ever knew about the low level on our whizzy Alphas, but I do remember a 1970s design which had (arguably?) a microkernel in hardware/firmwar

I'm not sure what I ever knew about the low level on our whizzy Alphas, but I do remember a 1970s design which had (arguably?) a microkernel in hardware/firmware, was fast, and supported an A1/B3-level OS: https://en.wikipedia.org/wiki/GEC_4000_series#Nucleus https://en.wikipedia.org/wiki/GEC_4000_series#Nucleus