[time-nuts] World's most accurate PC clock!

Poul-Henning Kamp phk at phk.freebsd.dk
Sat Jul 2 16:11:48 EDT 2005

In message <a05210600beec95afd329@[]>, 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).

Works great.

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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