Date: Sun, 30 Sep 2001 21:35:06 -0600 From: Warner Losh <imp@harmony.village.org> To: Bart Kus <bsd@shell-server.com> Cc: hackers@FreeBSD.ORG Subject: Re: precise timing Message-ID: <200110010335.f913Z6701389@harmony.village.org> In-Reply-To: Your message of "Sun, 30 Sep 2001 10:18:01 CDT." <200109301010.07784@EO> References: <200109301010.07784@EO>
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In message <200109301010.07784@EO> Bart Kus writes: : Right now, I use for() as a timing loop. I calibrate it on program start : and can then get very precise timing. There are, of course, the intermittent : interruptions of the multitasker. So this solution is not ideal by any : means. In fact, the for() loop approach is really meant for the DOS port of : this software. I'm wondering if there is any way I can access a more precise : interrupt-driven (or blocking) timing source. I know I can do a select() : with supposedly microsecond accuracy, but I doubt that it is in fact that : accurate in practice (doesn't the kernel only use a 100Hz clock or : something?). Is there any way to get at the system timers on the : motherboard? Those can provide precise timing, no? you are likely better off implementing this as a device driver, likely with the parallel port bus stuff. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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