The first two VAXen, the 11/780 and 11/750, both had TOY clocks that
ran when the machine was powered off. The 11/730 was designed to be a
low-cost VAX, and one of the ways they lowered the cost was
elimination of the TOY clock. VMS (and I assume also UNIX) asked you
to enter the time whenever you cold booted the 11/730.
After the 11/730 came out, Dick Hustvedt (lead VMS architect and
engineer) and Stan Rabinowitz put together an elaborate April fool's
hack. On April 1, the 11/730 in the VMS group's machine room had next
to it a pedestal with a sundial on it and a ribbon cable leading into
the 11/730, with sales brochures placed next to it. The sales
brochures announced the SD730 Fixed Head Solar Horologue, a sundial
with a photocell for detecting noon that could be used to
automatically set the 11/730's time-of-day clock. The thing actually
worked--it was connected via a UNIBUS real-time device controller, and
Hustvedt had written a VMS device driver for it.
All VAXen after the 11/730 had TOY clocks.
-Paul W.