1. How accurate is StarTrak?

2. Some computerised databases contain over 12000 objects, whereas StarTrak's database contains only about 250. Why is this?

3. Why Psion?

4. Will StarTrak run on the Psion Series 5?

5. Will StarTrak run on the minimum spec 128k Series 3?

6. Does StarTrak show the positions of the planets?

7. Do I have to keep adjusting StarTrak's GMT setting as I move to different timezones?

8. Under 'Making Setting Circles' there's a photo of an azimuth circle. It appears that the cut-outs for the PTFE support pads are not symmetrical. Why is this?

9. Can I use 'short-cut' keystrokes instead of selecting from the menus?

10. I notice that under the 'Object' group of menu options there is a 'Find' option. This seems to have the same effect as pressing the space-bar (to find another object).

11. How can I search for specific objects in the database?

12. When I select the 'About' menu entry, it tells me that my copy of StarTrak "will expire on 1^st January 2038." Why?

 13. Can StarTrak run on a PC?

The altitude and azimuth readouts from StarTrak are accurate to within a small fraction of a degree (provided you have the correct RA and DEC for the object, and the Psion's clock is accurately set). Other factors tend to be more important; these include (for a Dobsonian):

• Is the telescope level?
• Are the two altitude pivots at the same height?
• Is the azimuth circle centred accurately?

Ironically, the runaway success of the Dobsonian design is largely because it does not need to be precisely engineered. Despite this, StarTrak will work very well with most Dobs - you will be very unlucky if the star you are seeking is more than a degree out from its expected position on the azimuth or altitude scales.

Part of the philosophy behind the design of StarTrak was to enable you to add and edit the details of objects in the database, rather than overloading you with objects of little interest. So if there's an object you want to look at which isn't in the database, you can add it - the minimum data you need to know are its RA and DEC (and a name!) Or to put it another way: if you had a database of 12000 objects, just how many of those objects would you want to observe?

The Psion range of computers was chosen for StarTrak for a number of reasons:

• A Psion computer is very easy to carry - you can slip it in your pocket
• It will run for several weeks on a pair of AA-cells (a portable laptop computer will give up after a few hours on battery power)
• A Psion 'fires up' immediately - no long wait while the operating system loads up from disk.
• Compared to some computerised systems, the screen of a Psion can display lots of useful information - StarTrak can display up to four alternative names for the same object, its magnitude, distance, constellation name, RA and DEC as well as altitude and azimuth.

For someone with a Psion computer this really is a very low cost option to fitting other computerised systems requiring shaft encoders. It also means that at a star party, the same computer can be shared by several observers.

There are quite a few second-hand Series 3 Psions (and recently Series 3a and 3c Psions) available at bargain prices (usually from people who have upgraded to other Psions). StarTrak will run on the Series 3 as well as the 3a,3c, and 3mx Series, and there is a separate version for the epoc operating system, i.e. the Psion Series 5, Series 7, etc.

The version of StarTrak for the Series 3, 3a etc will not run on a Series 5 - there is a separate version of StarTrak for Symbian EPOC32 computers (the Psion Series 5, Series 7, Revo, Ericsson MC218 and others). This can be downloaded from the epoc32 download page.

The 128k Psion Series 3 will run StarTrak, but only if the Startrak.opo executable file is located (and then run from) a flash memory card. This is to leave sufficient memory in the Psion to hold the star catalogue and enough free memory to run the application.

Yes. This functionality was added with release version 3.

Only if you're adjusting the Psion clock to the local time in those timezones (e.g for your appointments diary), otherwise do not adjust the StarTrak GMT setting, even if you are observing the sky from different timezone locales.

I was rather sleepy when I cut this setting circle. We all make mistakes. The setting circle still works fine though, and with the rocker box on top no-one can see the cut-outs!

Yes, but only on the Series 3...3mx range (not the epoc-based machines) - for example, to add or edit details of an observatory, with the 'Psion' key held down (bottom-left of Psion keyboard) press the 'A' key. This has just the same effect as selecting 'Add/Edit' from the Observatory group of menu options. The short-cut keystrokes are displayed on the menus.

Yes, that's right. Since you will probably want to look at several objects during a night's viewing, StarTrak was designed to make it easy to change the selected object, and so the space-bar was programmed as an additional 'short-cut' to the 'Find' option.

An object in the database can be identified by any one of four possible alternative names - its Messier number (e.g. M13), NGC number (e.g. NGC6205), its common name (e.g. Aldebaran) or its 'Bayer' name (e.g. Alpha Tauri). These four alternatives are necessary because not all objects have Messier numbers, not all objects have NGC numbers, and so on. You can use 'wildcard' characters too - an asterisk means 'any number of characters', and '?' means a single character. For example, if you are using the 'List' menu option, then *nebula* will list all the objects with 'nebula' (or 'Nebula') in their names.

The internal clock in the Psion 3 Series will stop updating programs from January 2038 - in other words, the Series 3 Psions were only ever designed to work up to this date. Quite possibly my Psion will still be working up to this date, and I hope I will too...

Perhaps there will be further updates to StarTrak over the coming years, but it's more likely that StarTrak will be ported to a different kind of computer. Keep an eye on this website.

StarTrak (the Series 3 version) can run on a PC if that PC has the Series 3 (or 3a etc) emulator, and if that PC is running one of the older versions of Windows. For example, I know the emulator works well with Windows 95 and 98, but appears to no longer work with Windows XP. A zipped copy of the Series 3 emulator program called S3emul.zip (written by Psion PLC) is available by clicking here.

Please note that neither ST Software nor Psion PLC (the authors of the emulator) can offer any support regarding installation and use of the emulator.

There is a different emulator for the epoc-based machines (Series 5, Series 7, etc) and this works with later versions of Windows too. You might need to search the web to track down a copy.

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