ASCOM Star Book Driver

No Longer Supported

Please note I am no longer supporting or developing this driver. I had a long love/hate relationship with my Sphinx and the lack of official support from Vixen but hate ultimately won.

Decent mount hardware but the Starbook and its software just doesn’t work as a serious front end.

I will keep this page up for historical reference purposes and host the last release of my ASCOM driver.


The Sphinx GOTO mount from Vixen Japan has a number of highly innovative features that make it a one of a kind at present.

One particularly tantalising feature is the ability to communicate with the Sphinx via a network interface. Unfortunately Vixen Japan have shown no interest in providing English software to utilise this interface.

As I do not speak or read Japanese and in the interest of being able to control the Sphinx myself, I have developed an ASCOM driver for the Sphinx to allow it to be managed from any ASCOM compliant program.

This driver has been developed with little or no support from Vixen Japan and to date they have not officially recognised its existence. It has been entirely a labour of love (and some pain!) for myself and I decided early on to make it freely available to the Sphinx community – I hope you like it!


2004-08-17 The first release of my ASCOM Sphinx driver that allows current pointing position of Sphinx to be displayed in ASCOM compliant planetarium software.

2004-09-30 Vixen announced in their Japanese 1.2 build 24 update that the firmware would allow control of the Sphinx via the Japanese language only planetarium software StellaNavigator from AstroArts. Vixen state they have no plans to provide support via an English language product.

2004-10-10 The first version of my ASCOM Sphinx driver that allows ASCOM compliant planetarium software to control the Sphinx pointing position.

Note that ASCOM is a Microsoft Windows only solution at present so this will not be usable by MacOS or Linux users – sorry about that.


ASCOM logoStatus: Release
Download 4.40

  • You need to have Star Book firmware 1.2 build 26 or later.
  • You need to have ASCOM platform 4.1 or later installed.
  • Download the latest ASCOM Sphinx driver by clicking the link above.
  • Run the installer and fire up your favourite Planetarium or other telescope controlling software.


POTH dialogue

In order to control the Sphinx from your computer you will require ASCOM compatible client software. Cartes du Ciel and Starry Night Pro 5.* are a couple of planetarium applications along with more specialised software such as GuideDog. You can find a full list of ASCOM compatible clients at the ASCOM web site.?

To get started you can use POTH (short for plain old telescope hub) which is provided with the ASCOM installation. You can find this in your Start Menu under ASCOM Platform/Scope-Dome Hubs.

The first time you fire up POTH you will need to choose a telescope driver. You can do this by clicking the Setup button which opens the POTH Setup dialogue (not shown). In the top right corner of the setup dialogue you will see a button titled Choose Scope. Clicking this should display the ASCOM Telescope Chooser dialogue.

ASCOM chooserIf the ASCOM Platform menu or POTH is missing then ASCOM is not correctly installed.

?Select Sphinx from the pulldown list. If Sphinx is not listed then the Sphinx ASCOM driver is not correctly installed.

Assuming Sphinx is available, before clicking OK, click the Properties button to display the Setup dialogue for the Sphinx driver itself.

When the Vixen Sphinx Driver Setup dialogue is first displayed it will have a default IP address displayed and the status will be Unknown with many of the fields shaded grey.

It is almost certain that the default IP address will be incorrect and you will need to change this to match the IP address displayed in the Star Book. You can find this by pressing the Menu button on the Star Book then scrolling ?down to the About STAR BOOK entry in the System Menu. Change the IP address in the Setup dialogue to match that of the Star Book and press the Check button. This will attempt to connect to the Sphinx and retrieve information such as longitude and latitude as well as the firmware version installed on the Star Book.

ASCOM Star Book setup dialogueIf your firmware is older than the minimum version support by the Sphinx driver, a message will be displayed and you will need to update the firmware.

Assuming the IP address is correct and a network connection can be establised to the Sphinx, the status should change to Okay and many of the fields will be shaded bright green. Don’t worry about the other settings for now and press Okay.

You should now be back at the POTH Setup so click OK again to return to the main POTH window. Click Connect Scope and the fields at the top of the window showing the position of the telescope should now be updated.

Change the pulldown list from 30° to 5&ddeg; and click one of the compass directions. The telescope should now perform a short slew in the specified direction. If this works as expected then the Sphinx driver is properly configured.

Configuring the Sphinx in other applications is done in a similar manner and if you followed the POTH setup above, ASCOM should already be configured to use the Sphinx driver and it will most likely be a simple matter or telling the client software to use ASCOM. Support for specific clients is outside of the scope of what I support and you should join the ASCOM or Sphinx discussions on YahooGroups for assistance.

If you have have made a donation as thanks for my efforts in providing this driver, you can send me an email directly and I’ll do my best to assist.




Fix: Enhance polling check for position and time to avoid possible rentrancy.

Update: Remove some optional ASCOM settings including Aperture, Diameter, FocalLength and SiteElevation that were only implemented in the driver itself and had no affect on mount operation.



Fix: Change implementation of CanMoveAxis to remove incompatibility issue with Starry Night Pro.



Fix: Decimal minutes in RA were not correctly converted in non English versions of Microsoft Windows resulting in a rounding error.



Update: Remove support for AltAz methods as these are not directly supported by the hardware and are redundant.

Fix: Return value for RA and Dec may not be current due to polling interval.



Fix: Problem where cached responses get corrupted causing type mismatch errors in some situations.

Fix: Error generated due to mismatch in variable type for Soft Error and Reset Mount options.

Fix: Return value for RA and Dec may always not match actual RA/Dec due to polling interval.

Add: Start converting driver into a telescope hub.



Add: Soft Errors option to suppress raising error events. This is mostly useful for testing new scripts.

Add: Reset Mount option that allows you to reconnect to the Sphinx without the driver resetting it. This is mostly useful if you lose connectivity and want to reconnect but allow the mount to continue tracking. If the Star Book is in the initial startup state you will need to manually progress to the Chart/GOTO mode.



Update: Rework setup dialog handling of connection to the Star Book to provide more conservative connection attempt and more accurate error messages.



Fix: Reworked handling of concurrent network requests to eliminate driver hanging problem.


Release Candidate


I have experienced a number of unexplained crashes and hangs with the driver in this update. Please let me know if you have any problems!

Add: SyncToAltAz, SyncToCoordinates, SyncToTarget


Release Candidate


I have experienced a number of unexplained crashes and hangs with the driver in this update. Please let me know if you have any problems!

Update: Major rewrite of network interface code to support setting properties on Star Book and improve reliability of responses.

Fix: PulseGuide was incorrectly using duration in seconds rather than milliseconds(!).

Add: Altitude, Azimuth, SlewToAltAz, SlewToAltAzAsync

Update: Get SiteLongitude and SiteLatitude from Star Book.

Update: Get UTCDate from Star Book.



Update: Tweak handling of no valid connection to make display of SetupDialog faster.

Moved from Beta to Release status!



Fix: Home now works correctly.

Add: GuideRateDeclination, GuideRateRightAscension



Fix: Rework code for network connection to not rely on setup dialog. This completely removes topmost window error and ensures consistent re-entry into telescope object.



Fix: Remove topmost window error produced in some ASCOM clients. This may cause the setup dialog to appear underneath some badly behaved applications.



Fix: Check for ability to connect in SetupDialog could return Not Found even if there was no problem.



Fix: Remove check for ASCOM platform 4.0 for now as it is not publicly available and produces a couple of minor error messages.



Fix: Look for astro32.dll in same directory as the driver.



Fix: Corrected problem in installer that caused the driver not to register correctly in many circumstances.

Add: Initialise Star Book state for consistent behaviour.

Add: Set Star Book to maximum slewing rate for faster slews. Star Book automatically steps down as it approaches target.



Update: Updated installer to create required ASCOM registry key for first time installation. No changes to the driver.



Add: AbortSlew, CommandBlind, CommandString, PulseGuide, SiteLatitude, SiteLongitude, SlewToCoordinates, SlewToCoordinatesAsync, SlewToTarget, SlewToTargetAsync.

Moved from Alpha to Beta status!



Update: Revised version number to be consistent with forthcoming ASCOM Platform 4.0

Update: Upgrade driver to ASCOM Platform 4.0.

Update: Replaced sidereal calculation with one based on Meeus.

Fix: Error in N/S and E/W handling on setup form.

Add: ApertureDiameter, ApertureArea, FocalLength.



Update: Switch installer to Inno Setup. Remove unused files from previous installer.



Fix: Fixed problem with some ASCOM clients having a problem connecting immediately after using the Setup dialog.

Add: Allow choice of polling interval.



First public release

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  1. Tom Narwid says:

    I have a Starbook and would like to know if I load your driver will it wipe out the original driver in the Starbook and will the Starbook work with The Sky version 5.
    I don’t want to do anything that will erase the original driver and firmware that operates the Starbook.

  2. My ASCOM driver is like glue between ASCOM compliant astronomy software and the Star Book. It doesn’t modify the Star Book in any way.

  3. Graham Elton says:

    Hi Peter,

    I have been using your Sphinx ASCOM driver for a year without any problems
    so its about time to show some thanks. Your bank account details would help!


  4. Glad to hear it is working well! You can find bank account details on the download page.

  5. Marques says:

    Hi, I installed your drive a while ago, and although I usually don´t use it bacause I still don´t control the mount with my telescope except for autoguiding, the tests that I did when I installed it were very satisfaying. Congratulations and thanks for sharing your work for free.

    Anyway, I recently reinstalled the OS, and I just tried to install your driver again, but I couldn´t. The reason is that I now have V2.1 and your driver says that it is too old. I don´t know if that is a bug easy to fix and if you are still willing to do it, but I whould really apreciate it.

    Thanks in advance.

  6. Hi Marques. There is an issue with version detection (a throw back from when features in the firmware directly affected the driver). It is largely cosmetic and you should be able to ignore the error and continue.

  7. Jim Fusco says:

    Hi Pete,
    Thanks for the great job. You made mention of a update comming out and also updates to people who help support the driver program 2008. I have made support over a year ago, but haven’t seen updates.

  8. The current driver works well for most people. The update I have been very slowly progressing is mostly to ensure the driver remains compliant with the latest version of ASCOM and will also fix some bugs (which require more investigation and testing re the best solution).

  9. Hello Peter,

    We recently purchased a Vixen ED115S with an SXD Equatorial Mount and Star Book Ver 2.2. It replaced our trusty Celestron C8 that was stolen.

    So far we are quite pleased with the scope, have only been able to set it up a few times because of our inclement weather. Alice Springs has had more than its share of rain this past 6 months.

    Lucky you being 10 hours from Greenwich, our 9.5 hours is a constant headache but hasn’t seemed to cause too much trouble as yet.

    The Star Book is a bit of a mystery though. Call up Fomalhaut and we get Archenar and vice versa, last night we were pretty happy with the alignment found the Pinwheel galaxy without much trouble but Andromeda proved too elusive, the R.A. seemed OK but the DEC far too low, but easy to see naked eye. From this odd position we slewed straight to Betelgeuse and it was spot on.

    Karl who is not used to SMS or video games hates the buttons on the Star Book, he constantly pushes the wrong ones and has to start again and he put white-out on them so he could see them in the dark.

    I was pleased to find your web site at the top of the list when I googled this afternoon and wonder if anyone else has found errors in the Star Book like us.

    Regards Rosalie Kramer

  10. I’m not aware of the errors in the catalogue but it does sound odd. Have you updated to the latest firmware?

    People have a love/hate relationship with the Star Book. It is a novel format but the lack of visual/tactile context around the button locations does take some getting used to.

  11. Mike Blaber says:

    will the driver work with the Vixen Atlux with starbook?

  12. Jim Fusco says:

    Yes, I have the Atlux w/starbook.

  13. Michael Blaber says:


    thank you for writing this driver. I would like to have options to guide at 0.5x and 1.0x sidereal; however, it appears that 2x sidereal is the lowest. Can you provide the lower rates?



  14. The guiding is in part based on the current zoom level of your Star Book. You can try changing that while guiding but there was no obvious way to do this programatically.

  15. Adrien says:

    Hi Peter

    I have a Vixen Sphinx SXW and it’s working perfect. Using the driver celestial objects can be easily targeted by planetary software. Personally I am using Cartes du ciel.
    Even if most of the time beeing under a quite persistent cloud layer, I am progressing quite a bit in astrofotography and lately decided to move over to a notebook having long life batteries for an up to 8 hours use. This would keep me away from carrying extra load each time. The operating system is Windows 7 (64 bit) and the Sphinx driver was rejected due to incompatibility. On 32 bit operating systems it’s installed without problems. Does Is Vixen aware of that and do they possibly offer a solution ?
    It would be very much of a petty if the comfortable planetary software control would become impossible .


  16. Vixen couldn’t care less about computer control of their telescopes. ASCOM does work with Windows 7 however my driver would need to be completely rewritten. I’ve been very slowly doing that but I’m afraid this has slipped a long way down my priority list these days.

  17. Peter says:

    Hey Peter,

    I am going to buy the Starbook-S which controls the Vixen GP2 Mount. Is your driver compatible with the Startbook-S?


  18. Alexander Vocelka says:

    Hi Peter,

    I have downloaded your 4.4. driver and it works fine with the Starkbook S.
    I just wonder why it should be impossible to stop the sidereal tracking. The S enables tracking to be set in 20 steps from 0.1x to 2.0x sideral.
    Also the autoguider only seems to work on the y-axis. Which makes no sense as I can move both motors in parallel through the S.

    It would be worth 100$ if park and autoguiding could be fixed. Or if your driver was open source and I could employ some of my programmers to get it done.

    I will move to astrophysics gear next year but will have to stick with the Vixen part until then and want to test new cameras and a roof installed observatory (vibrations etc).

    Because your previous comment on Vixen’s interest in computer age astronomy is dead right: The Japanes companies have by and large missed the computerization of machines and are still trapped in their high-precision mechanical age. Sony’s Playstation is proof of this. Also Vixen’s Web Page is stone age like. It’s about time they woke up before people stop buying their mechanical parts. It’s the Kodak effect that has hit the Music and Video industry.

    If I was Vixen’s Product Manager for telescopes I’d ensured top notch drivers and a replacement of the S and any other paddle parts through the iPad. That’s how it will be. a small piece of USB connector Interface but otherwise handheld and finger-operated.

    So any suggestions how I could help or get to improve the driver myself is welcome.

    Otherwise: really admirable how you keep Vixen-Astronomy afloat with your expertise and service – chapeau!


  19. My driver was designed for the original SXW mount. I’m glad it works with later models but I obviously don’t have the equipment for testing. The SXW supported home but not park as it had no permanent state stored in the mount itself. Likewise it didn’t offer the same tracking features.

    Although I am a big supporter of open source, I don’t intend to open source my code for a variety of personal reasons. The code was originally written in VB6 and I am part way through a port to .NET (which is what ASCOM has moved to) but as noted elsewhere, I am making slow progress as I don’t have a strong motivation to do so given the driver meets my needs and the level of donations vs downloads doesn’t add any incentive.

  20. Peter Nerbun says:

    I’m running 64-bit Windows 7 on my laptop. My Starbook firmware is Version 1.2, Build 35. I started up POTH, clicked on the Setup button and clicked on Choose Scope. I selected Vixen Sphinx, clicked on Properties, entered the IP Address displayed in my Star Book and clicked on the “Check” button. The word “Check” went from black to grey; after about 10 seconds the word “Check” changed back to black and no information was transferred about Latitude and Longitude. I have the the Starbook-S which controls a Vixen GP2 Mount. Is the problem that I am running 64-bit Windows 7?

  21. Peter Nerbun says:

    I just wrote a question above. Since then I tried the same procedure on a Windows XP laptop and got the same results, namely that after I clicked on “Check”, I couldn’t go to the “Okay” stage of the Vixen Sphinx Driver Setup Screen. I forgot to mention that I used a Cat5e Network Crossover Cable to connect my laptop to the Starbook. Is that the correct cable to use?

    Thank you,

  22. I’m not sure about Win7. I’ve heard people mention issues with 64bit Windows but I don’t run it myself so can’t confirm. Not sure you need a crossover cable as most modern NICs handle this automatically.

  23. Peter Nerbun says:

    Hi Peter,

    I believe that the problem is that I’m not making a network connection between the Starbook-S and my Windows XP laptop. The Starbook-S instruction manual outlines a procedure for registering orbital elements for comets by connecting to a PC so I figured I’d try that capability first to see if I could make a connection according to their instructions. When I entered my IP address in the Internet Explorer address bar I didn’t see the Starbook-S screen that the instructions said would appear; instead my PC stated that no connection to that IP address could be made.

    Thanks for replying,

  24. T. Kawai says:

    November 8, 2012

    Dear Mr. Enzerink,

    My name is Toyohisa Kawai and I’m sending you this email as a messenger on behalf of a research and development section at Vixen.

    We understand you are a developer of ASCOM DRIVER for Sphinx and you have been distributing the driver for the Sphinx users on a site of ASCOM Standard for Astronomy. Thank you for your passion and endeavors you have done for making a platform that facilitates the operation of a Sphinx mount via a PC.

    Vixen is in the process of making ASCOM DRIVER for Sphinx and we would like to know if you are interested in sharing this software development with Vixen. We will provide you
    all the necessary information if you update your ASCOM DRIVER and keep taking care of it through your website.

    We look forward to hearing from you soon.

    Yours faithfully,
    T. Kawai
    Vixen Co., Ltd.

  25. Peter Nerbun says:

    Well I finally succeeded in connecting my Starbook-S to my laptop (now a Win 10 SP2). Rather than connect my laptop directly to the Starbook-S I re-read your instructions and connected the Starbook-S to my home network. Upon entering the IP address for my network on the Vixen Sphinx Driver Setup screen and pressing Check” my site information Latitude and Longitude appeared with a green background and the Okay indicator also lit up in green. I pressed OK at the bottom of the screen and I was connected! I use Carte du Ceil to select celestial targets and command the Vixen GP2 Mount to slew to them. Thank you Peter, it was a long effort but all’s well that ends well!

    Peter Nerbun

  26. Frode Nicolaisen says:

    Are there any plans making a 64-bit Windows 10 Version of this driver?

    Frode Nicolaisen

  27. Alex McCabe says:

    Just got a vixen mount with starbook
    just wanted to know if my win 10 64bit laptop would work
    or will I have to find an xp 32 bit windows to install
    regards Alex
    PS well done for all your hard work to date

  28. Torstein Jakobsen says:

    Hello from Norway. I cant find the Ascom driver for the Star Book that you made. I have connection between ipad and Vixen Sphinx /star book using SkySafari 5 pluss and its great connected to wifi extender, but
    I miss using the Stellarium and other softwares. Can you please e-mail me the driver?

    Best regards

    Torstein Jakobsen

  29. Ryosuke Kikuchi says:

    Hi. My name is Ryosuke Kikuchi.
    I am developing astronomical cameras. I have Vixen Sphinx and StarBook. I would like to try the auto guide with my camera and ASCOM, but I do not have the ASCOM driver you created.
    I could not find the ASCOM driver on your site.I would like to obtain your ASCOM driver for camera development. Can you please e-mail me the driver?

    Best regards

    Ryosuke Kikuchi

  30. Mauricio says:

    Hello from Mexico.

    Im trying to download the driver, but it is no longer available, could you please e-mail me the driver?

    Thank you very much in advance !
    You rock

  31. Link to last driver should now be working.

  32. Link to last driver should now be working.

  33. Link to last driver should now be working.

  34. Matteo Maggiora says:

    Hello Mr Enzerink, I tryed to download the ASCOM driver from the link above but it doesn’t work. 🙁

    Can you please provide me a copy via email?
    thank you very much


  35. Apologies, link should now be working.

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