RUS - 'Really Useful Stopwatch' for Psion 3c A Shareware Program by Kevin Millican Email: kmillican@compuserve.com This is the unregistered version of RUS. Registration costs £5 (UKP) or $10 (USD) when registered through Compuserve (GO SWREG and use ID16147). When you register you will receive a version without the annoying 'nag' screens via EMail or in the post if you send a cheque with an SAE. 1. DISCLAIMER 1.1 All software included in this archive is provided 'As-is' with no warranty of any kind. The author has taken care to ensure that this software is reliable and will not adversely affect the operation of other software or data integrity but no guarantee is given; you use this software at your own risk and by using it are signalling your agreement to these terms. 2. INTRODUCTION 2.1 RUS is a 1/100th second stop-watch for the Psion 3c. It should also work fine on the 3a and Siena. 2.2 I wrote this because I was unimpressed with existing stopwatches for the 3c which tended to perform poorly compared to the real thing and couldn't be used easily with user-written OPL routines. The timer uses the FRC: device which is a built-in timer that increments every 1/1024 of a second. There is a bug in the Psion internal routines that can cause an error in reading this timer from OPL resulting in occasional 30 second errors (about 1 in 0.5 million actually) but RUS traps this to provide a reliable and accurate device. 2.3 The main routine reads the keyboard about 150-170 times per second (to give 1/100th sec accurate starts/stops) and updates the continuous display about every 3/100ths of a second (faster than my eyes can follow!). 3. USAGE 3.1 Copy RUS.OPA to the \APP directory and install from the Psion system screen. 3.2 If you wish to call RUS from your own OPL programs, copy RUS.OPO to the \OPO directory. 3.3 The program uses four buttons :- 3.3.1 'S' starts and stops the timer. 3.3.2 'E' records an elapsed time without stopping the timer. 3.3.3 'R' resets the timer (only available when the timer is not running). 3.3.4 The key exits the program (only available when the timer is not running). 3.4 Times are shown in seconds and hr:min:sec.csec format. 4. USING RUS.OPO IN YOUR OWN PROGRAMS 4.1 The RUS.OPO program returns the final time in seconds to the theoretical accuracy of 1ms. 4.2 See USE-RUS.OPL for example code. 5. REGISTERING/FEEDBACK 5.1 I welcome comments/suggestions and new registrations (!). If you do not have access via EMail, I can be contacted at :- 20 St Johns Road Belton,Gt Yarmouth, Norfolk. NR31 9NS England, UK