[time-nuts] Re: When did computer clocks get so bad?

[ed breya]

I assume you're talking about the RTC chip that runs off the CMOS BIOS 
memory settings battery, to keep time whether the computer is on or off. 
These are as you suspect, typically cheap items that get the basic job 
done. You may be able to find better grade ones. It also depends on 
whether the timing crystal is built into the IC, or a separate piece. In 
this case, you could fairly easily hack in a reference that's as good as 
you want. Usually it's a 32.768 kHz "watch" type resonator, and 
disconnecting one end and hooking in an external source will drive it 
instead. If you provide the same nominal frequency, that's much more 
accurate and stable, can run the RTC under all conditions, and is always 
on, then it should keep time as good as your reference.

Ed