[time-nuts] World's most accurate PC clock!
phk at phk.freebsd.dk
Sat Jul 2 16:11:48 EDT 2005
In message <firstname.lastname@example.org>, David Forbes writes:
>It could easily be multiplied by 4 to make the canonical 14.318 MHz
>PC clock, so your DOS machine could be made to work at high stability
>and reasonable accuracy.
I've done that for years.
Most PC's will run from approx 13.8 to 15 MHz.
Usually I use a PLL chip (ICS525).
And btw, the 14.318MHz frequency is 4 x the color carrier in NTSC
because that's what IBM used to make the ghastly colors on the
orginal CGA adapter.
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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