Allegedly, on or about 18 May 2017, William sent:
"I didn't know workstations nowadays had batteries. When the
system is
back on its feet, I'll try to check that. It was bought in 2013."
I knew that the older motherboards had batteries. But I thought the
newer ones used something like flash (or other persistent) memory. It
did not occur to me that booting might want the date/time before the
boot process reached the point of being able to access the internet.
You can't store time. It's continuously changing.
There are a few ways of keeping a clock ticking while the power is
off:
Run the clock off a watch battery, and most systems do. It's always
running off the battery, even when the mains power is applied. It keeps
the clock independent.
Do so with a rechargeable battery, that the system recharges when it's
running. My sister's ancient Mac did that. I think at least one of my
Amigas did, too, if I recall correctly.
Use a super-capacitor. One that can hold a charge for a very long time.
Many VCRs used to do that. They're usually powered up all the time, but
used the super-cap to keep the clock running during power-outs, and
saving people the headache of resetting the clock if they needed to
unplug and move their VCR. Most computers are at least partially
powered up all the time (since few people actually switch them off at
the wall), or are powered up often enough to keep the clock running
until the next time that you switch on, so this is a mostly viable
option.
But the first option is going to be the most common approach in the PC
world.
--
[tim@localhost ~]$ uname -rsvp
Linux 3.9.10-100.fc17.x86_64 #1 SMP Sun Jul 14 01:31:27 UTC 2013 x86_64
Boilerplate: All mail to my mailbox is automatically deleted, there is
no point trying to privately email me, I only get to see the messages
posted to the mailing list.
Ha ha ha ha... (I couldn't think of a good joke, so I supplied a laugh
track, instead.)