kg —
KL-11/DL-11W line clock
kg0 at uba0 csr 0176500 vector kglock
NOTE: This driver has not been ported from 4.4BSD yet.
A KL-11 or DL-11W can be used as an alternative real time clock
    source. When configured, certain system statistics and, optionally, system
    profiling work will be collected each time the clock interrupts. For optimum
    accuracy in profiling, the DL-11W should be configured to interrupt at the
    highest possible priority level. The kg device
    driver automatically calibrates itself to the line clock frequency.
The kg driver appeared in
  4.2BSD.