Xref: utzoo comp.sys.mac.hypercard:1349 comp.sys.mac.programmer:3474 Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!ukma!rutgers!ucsd!ucbvax!dewey.soe.berkeley.edu!oster From: oster@dewey.soe.berkeley.edu (David Phillip Oster) Newsgroups: comp.sys.mac.hypercard,comp.sys.mac.programmer Subject: Re: Reaction Time stacks : can I do this? Message-ID: <27081@ucbvax.BERKELEY.EDU> Date: 9 Dec 88 17:15:53 GMT References: <6012@mva.cs.liv.ac.uk> <21792@apple.Apple.COM> <21826@apple.Apple.COM> <3820@pt.cs.cmu.edu> <794@husc6.harvard.edu> Sender: usenet@ucbvax.BERKELEY.EDU Reply-To: oster@dewey.soe.berkeley.edu.UUCP (David Phillip Oster) Organization: School of Education, UC-Berkeley Lines: 19 If you use a digitizing tablet connected to the Mac serial port at 19.2KBaud, you'll be talking at about 2kBytes a second. Since it takes about 5 bytes for a tablet to send a position record (depends on the brand of tablet.) it takes 2.5m sec to get the position data. This means that you can't measure events that are closer together in time than that. However, since the tablet introduces a uniform delay, and since it begins transmitting as soon as the pen comes within range of the tablet, you can measure events to an accuracy greater than 2.5ms. Just watch out for tablet continuous mode: in this mode many tablets transmit as infrequently as one hundred times a second. Once again, you'll need to draw the images yourself, rather than leaving them for hypercard to draw, and be sure to allow for the fact that the drawing is quantized in time by the video hardware to be no faster than 60 times a second. --- David Phillip Oster --"When we replace the mouse with a pen, Arpa: oster@dewey.soe.berkeley.edu --3 button mouse fans will need saxophone Uucp: {uwvax,decvax}!ucbvax!oster%dewey.soe.berkeley.edu --lessons." - Gasee