Path: utzoo!attcan!uunet!samsung!zaphod.mps.ohio-state.edu!sdd.hp.com!elroy.jpl.nasa.gov!ames!uhccux!virtue!ccc_ldo
From: ccc_ldo@waikato.ac.nz (Lawrence D'Oliveiro, Waikato University)
Newsgroups: comp.sys.mac.programmer
Subject: Re: High-resolution timing?
Message-ID: <1171.26beff78@waikato.ac.nz>
Date: 7 Aug 90 05:50:48 GMT
References: <1822@mountn.dec.com>
Organization: University of Waikato, Hamilton, New Zealand
Lines: 29

To time things to better than single-tick resolution, you need the
Time Manager. The original Time Manager is documented in chapter
32 of the New Testament (Inside Mac Vol IV), and lets you invoke
tasks at intervals measured to millisecond resolution.

System 6.0.3 introduced the Revised Time Manager, which gives you
the option of microsecond resolution (just pass a negative tmCount).
You can also use the Revised Time Manager to measure unknown intervals,
without necessarily invoking a task: the way this works is, if
you call RmvTime before the timer has gone off, the tmCount field
will contain the number of time units (milliseconds or negated
microseconds) remaining until the timer would have gone off.

The above information is from the interim Inside Mac Vol VI
documentation on the System 7.0a9 CD-ROM (I don't have 7.0a12,
sigh...). This also mentions the Extended Time Manager in
System 7.0, which adds a few new interesting functions.

Tech Note 180 has a few more hints about the Revised Time Manager;
on or about page 7 (my copy may have been reformatted a little),
in a section labeled "Time Manager Tasks", it says that your
timer task now gets the TMTask record address in A1, and it no
longer needs to worry about setting up A5.

Lawrence D'Oliveiro                       fone: +64-71-562-889
Computer Services Dept                     fax: +64-71-384-066
University of Waikato            electric mail: ldo@waikato.ac.nz
Hamilton, New Zealand    37^ 47' 26" S, 175^ 19' 7" E, GMT+12:00
Finally, a message for all power users: pay your electricity bills!