NMI /N-M-I/ n.
Non-Maskable Interrupt. An IRQ 7 on the PDP-11 or 680[01234]0;
the NMI line on an 80[1234]86. In contrast with a priority interrupt (which might
be ignored, although that is unlikely), an NMI is never
ignored. Except, that is, on clone
boxes, where NMI is often ignored on the motherboard because
flaky hardware can generate many spurious ones.