This package is essentially a set of functions to help writing reaction time experiments on the Mac, the KeMo Reaction Timing Utilities. Functionality currently consists of the following:
- a timer with 20 microsecond resolution
- polling functions for ADB devices, such as keyboards and mice, with +/-1.4 to +/-2.1 msec accuracy, depending on your Mac (as opposed to the +/- 8 to +/-16 msec accuracy that you get with "normal" Toolbox functions like GetKeys)
- a screen refresh synchronization function for all Macs
- functions that hide and show the menu bar
Before I get too many comments like "the Mac is not a real-time machine" let me put in my disclaimer: this software-only approach does not guarantee the accuracy claimed above in all conditions. Various factors like disk access and network activity can cause loss of accuracy. But this lack of accuracy can be avoided with careful programming and by using Macs that are not doing a zillion other things and running a zillion other programs at the same time they are doing reaction timing. See "Accuracy Issues" in the Users' Guide for more discussion of this.
These routines are packaged in a library file which can be incorporated into your program. Additionally, a sample program that exercises all of the functions is included with source code in C.
KeMo╒s ADB (Apple Desktop Bus) polling functions only work on Macs with ADB╒s. These include all Macs sold by Apple after the Mac Plus. Some incompatibility has been detected with PowerBooks, but other Macs, from Classics to Quadras, all work fine. In addition, all functions require System Version 6.0.5 or later.
The KeMo set of functions is distributed as ╥Old World Order/Recession-ware╙: there is a shareware registration fee of $20 unless you can't afford it, or can't get U.S. dollars. You may not use KeMo to write commercial or shareware programs without prior permission. See the license terms in the Users' Guide for more details.
You may contact Dan Costin, the author, at dcostin@ucsd.edu or dcostin@ucsd.bitnet,
