Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!dewey.soe.berkeley.edu!oster From: oster@dewey.soe.berkeley.edu (David Phillip Oster) Newsgroups: comp.sys.mac.programmer Subject: Re: mac programming question Message-ID: <28799@ucbvax.BERKELEY.EDU> Date: 15 Apr 89 07:34:25 GMT References: Sender: usenet@ucbvax.BERKELEY.EDU Reply-To: oster@dewey.soe.berkeley.edu.UUCP (David Phillip Oster) Organization: School of Education, UC-Berkeley Lines: 16 In article dk1y+@andrew.cmu.edu (David Kosmal) writes: >I am interested in developing a simple program for a psychology experiment that >will measure the time interval between a the appearance of a display on the >screen and when the viewer presses a key. This time interval must be measured >within 1/100th of a second. You can measure time this short using the Time manager, (documented in Inside Mac Vol 4.) Be sure to calibrate it. It is documented as giving you a time interval resolution of .01 seconds, but my tests showed that at least on my machine it was more like .011 seconds. Another problem: I believe that the keyboard and mouse button are only polled at most 60 times a second. If you want to go faster, consider using a simple switch that changes the level of the CTS line of the serial port. (Be sure you know what you are doing before shorting wires in the serial port!) Thunderscan works by toggling the handshaking wire: the rate it toggles the wire is porportional to how much light is being reflected back into the light sensor.