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5. Other Considerations

5.1 Screensavers

Depending on where you deploy your kiosk, you may not want all the default xscreensaver images to appear. For our Hands-On Biodiversity Gallery we wanted to display only the animated fractal images that suggested life science themes.

After testing out several screensaver images, we decided that we to select randomly between two choices: coral and forest.

To limit xscreensaver to displaying these two, we created the file .xscreensaver in the filesystem root (/) with the following options:

/.xscreensaver


programs: \
        coral -root \n\
        forest -root \n

5.2 Sound Files

Our kiosk machine contains a Sound Blaster AWE64 card with attached speakers. We chose this card specifically because it works well with Linux sound drivers.

The MySQL database that drives our Biodiversity Gallery kiosk points to a collection of sound files that a visitor may listen to, including a ``bird song quiz.'' The downside of using Linux Netscape for a kiosk is that some of the multimedia aspects are primitive, compared to Windows and Macintosh.

To enable sound, we implemented a Unix Netscape plugin called Xswallow written by Caolan McNamara ( http://skynet.csn.ul.ie/~caolan/docs/XSwallow.html). All the sound plugins we tested create a separate web page as the sound is being played (unless the sound file is embedded). Of the programs we tested, Xswallow worked the best and had the cleanest display page.

Although the extra page is inconvenient, we decided that having the stability of Linux was more important than the extra click required to return to the previous screen.

An additional problem is that when a sound is selected, the Xswallow page displays ``Click to Abort Swallow of type audio/basic''. Clicking merely returns a blank page. I made a slight change to the author's source code for UnixShell.c, changing

char *text2 = "Click to Abort Swallow";

to read

char *text2 = "Click BACK Button to return from playing file";

The phrase ``of type audio/basic'' appears to come directly from Netscape rather than Xswallow.

After recompiling, I added the plugin to Netscape.

A last note about sound files: the original set of files we received were a mix of .au and .wav files. Our experience was that the .au files worked the most reliably in Linux and we converted all sound files to .au format.

5.3 Trackballs

Not having the funding for a touchscreen display, we opted for a trackball (and no keyboard) for our kiosk navigation. Our colleague, Andy Rauer at the Ontario Science Centre in Toronto, tipped us off to using ``industry-strength'' trackball components from Happ Conrols Inc., Elk Grove Village, Illinois http://www.happcontrols.com/ (check under their Interactives section).

One of the things we needed to do was disable any right-mouse button click equivalents from being used in Netscape Navigator because right-click events invoke user dialogs.

By building our own trackball, we were able to wire it any way we wanted. We wired in two push-button controls, both with a left-mouse button equivalent. The buttons are arranged on either side of the trackball, allowing ease of use from right-handed and left-handed visitors. Our gallery designers then took the trackball parts and built them into the gallery's kiosk enclosure.

For our kiosk we purchased the following components for building a heavy-duty trackball designed to withstand visitor use (and abuse):

From a local electronics vendor, we purchased a Hammond Manufacturing plastic handy case (Cat no. 1591ABK) for housing the electronics board for the trackball.

Anticipating additional kiosks, and potential part failure, we ordered four sets of each of the above for spare parts and testing.

5.4 Designing or modifying HTML pages for kiosks

In the best of all possible worlds, you will have the opporunity to design your kiosk pages from scratch. Bearing in mind that using a kiosk is a different experience from sitting at a desk browsing the web from a personal workstation, the following guidelines are useful design principles:

Unforunately you will sometimes inherit pages that were designed for web browsing rather than kiosk browsing. In these cases it may be too time-consuming or too difficult to redesign them as kiosk pages. When implementing standard web pages for a kiosk display:


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