Drifter

Drifter -- Clock Drift Compensator

Drifter is a simple utility program designed to keep your PDA system clock accurate without the need to synchronize with an external time server.

The system clocks on most computer systems are not very accurate. In fact, it is not unusual for the clock to 'drift' several seconds each day. Over the course of weeks or months this error can add up resulting in a clock that is several minutes fast or slow. On a PDA - a device designed to keep track of your schedule and remind you of important events - an inaccurate clock is a bad thing.

Servers and desktop PCs solve this problem by periodically connecting to a time server on the local network and synchronizing their clock. But for a PDA, relying on time server synchronization may not be practical.

Drifter solves that problem by determining the amount of error in the system clock. Drifter then automatically adjusts the system clock at the exact intervals required to compensate for the error.

Main

Using Drifter is easy! When Drifter starts you'll see a clock showing the current system time, some information about how much time the clock gains or loses, a checkbox to enable automatic corrections, and a couple of calibration buttons.

When you first start using Drifter you will need to calibrate it. If your Zaurus can access the internet, you can use the Net Calibrate button, otherwise use the Calibrate button. See the Calibrate or Net Calibrate sections for detailed calibration instructions.

After your first calibration, exit Drifter and ignore it for a few days. Then run Drifter again and repeat the calibration process. The idea at this point is to wait long enough for the system clock to 'drift by at least a second. The longer you wait the more accurate the calibration will be. We recommend at least four days.

Once you've completed the two calibrations, Drifter is ready to start making clock automatic clock error corrections. Use the Enable checkbox to turn automatic corrections on and off.

You can re-calibrate Drifter at any time after the initial calibration. It's a good idea to do this a few weeks after the inital calibration to fine tune Drifter's corrections. Typically, the only other time you'll want to re-calibrate is if you notice that the clock still isn't keeping perfect time.

Calibrate

The Calibrate button takes you to the "manual" calibration screen. You will see a display of the current time with buttons to adjust the minutes and seconds up and down.

Using an accurate time reference, set the clock to the right time with the adjustment buttons and then tap the Ok button. This will set the system time and also allow Drifter to calculate the amount of error in the clock so it can make adjustments in the future.

The Set Only button allows you to make changes to the clock without affecting Drifter's calibration. Under normal circumstances, this button should not be used.

The Uncalibrate button allows you to erase Drifter's calibration data so that you can start the calibration process from scratch. Use this if something causes Drifter to get confused about the amount of clock error.

Net Calibrate

The Net Calibrate button takes you to the "automatic" calibration screen. You will see a box to enter the time server's network address and several buttons.

Note: your Zaurus must have an active connection to the internet or a local network with an NTP time server to do automatic calibration.

This mode of calibration communicates with a network time server (using the NTP protocol) to get the correct time. This is not necesarily any more accurate than manual calibration, but it is easier.

Enter the network address (this can be a name or an IP address) in the Server box. You can also tap on the arrow next to the box to select from a list of known internet time server all over the world. Note that not all of the servers on this list are guaranteed to work, so if you have problems with the selected server, try another. The screen also tells you where to go to get an up-to-date list of time servers. When your server is selected, tap the Set button and Drifter will get the correct time from the server, set the system clock to match, and compute the amount of error in the clock.

The Set Only button allows you to make changes to the clock without affecting Drifter's calibration. Under normal circumstances, this button should not be used.

Register

Drifter is available as a free download so you can try it out and see if you want to purchase it. In this "trial mode" Drifter will work normally until it has performed ten automatic clock adustments. The actual amount of time this give you will vary depending on the amount of error in your system clock, but for the most part it will allow drifter to run for a few days after automatic adjustments are enabled. That should be sufficient time to let you decide if Drifter is worth purchasing. Note that you have as long as you like to perform the initial two calibrations.

You can purchase Drifter from handango.com. Kopsis uses Handango as our exclusive distributor for this software. Handango accepts many forms of payment and allows you to order online, by phone, or by mail. See Handango's website for more information.

Once you purchase Drifter, you'll get an email from Kopsis with a link to a web page where you will complete the registration process. Use the Registration... item in the Options menu to bring up the registration form. The form will display your Registration ID which you will enter into the form on Kopsis' website. The website will then give you a registration code which you enter into Drifter's form. If you enter a valid code and then tap the Ok button, your copy of Drifter will now be registered and will run without any limitations.

Support

Here are some helpful tips for using Drifter:

You don't have to leave drifter running for it to maintain your clock. Drifter automatically schedules periodic 'wake-up calls' so it can do its work.
Qtopia applications are supposed to be able to respond to a 'wake-up call' without bringing up the application's user interface. However, a bug in the current Zaurus ROMs prevents this from working correctly. When Drifter is activated to do an automatic adjustment, it will stay 'open' after the adjustment is complete. This does not cause any problems - simply click the close button to dismiss Drifter.
Once drifter is fully calibrated, doing the calibration again after a longer period of time (one or two months) may improve accuracy. You can fine tune the calibration any time you notice that your sytem clock no longer matches your reference simply by running Drifter and tapping Calibrate Now.
If you restart QPE, you will need to run Drifter to restart it's automatic clock adjusting.
Drifter includes a console application called dntpdate. This is simply ntpdate from NTP 4.1.72 compiled to run on the Zaurus. This utility can be used from the console, however setting the system clock without Drifter's knowledge can lead to inaccurate calibration.

If you have questions about or problems with Drifter that aren't covered in this online manual, feel free to contact Kopsis customer support via email at support@kopsisengineering.com