Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!husc6!sri-unix!larson
From: larson@unix.SRI.COM (Alan Larson)
Newsgroups: sci.space.shuttle
Subject: Re: holds in countdown
Message-ID: <29420@sri-unix.SRI.COM>
Date: 8 Apr 89 08:51:15 GMT
References: <8.UUL1.3#5131@mvac.UUCP> <1989Mar22.175252.1343@utzoo.uucp> <2515@phred.UUCP> <1989Mar28.233955.1843@utzoo.uucp>
Reply-To: larson@unix.sri.com (Alan Larson)
Organization: SRI, Menlo Park, CA.
Lines: 25

In article <1989Mar28.233955.1843@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:

>You miss the point.  That's an excellent reason for having some slack time.
>The original question, though, was why the countdown clock stops during the
>reserve time.  There's no obvious reason why it couldn't keep counting --
>the lengths of those periods are fixed and predictable if nothing goes wrong.
>It's a bit silly to have the clock stopping and starting when everything is
>going according to plan.

A couple of reasons.

    o	If the clock is stopped, and you extend the hold a short time,
	it is easier to continue with everything still on the time
	schedule than if you have to reset the clock to the end of the
	'idle' time before continuing.

    o	If the end of the 'idle' time is coming up, it is easier to
	continue the hold than to stop the clock.  It has to do with
	the difference in answering the questions: "Is everything right"
	and "Is something definitely wrong".
	It is easier for someone to say, "Don't continue yet, we should
	check this", when approaching the end of a hold than to say
	"Stop the countdown, I want to check something."

	Alan