Frequently Asked Questions

Questions:

1. Could you let the trains run a bit slower?
2. What about recording 30 secs MPEG and sending it to the client?
3. I get only still images.
4. Are the GIF stream encoder software and the modified browsers available?
5. Will you add the inline video to Mosaic?
6. How about a larger layout?
7. Nothing happens. I only get the comment "And silence filled the night"?
8. How did you link the trains with the computer?
9. IT DOES NOT WORK
10. Video stops when starting train
11. How to make a counter?
12. How can I animate in NetScape/Mosaic?
13. Why can I see the trains moving (hopping) while the GIF test page shows no video ?
14. Is it real or just some recorded videos ?
15. Why do the pages look so bad ?
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Answers:

1. Could you let the trains run a bit slower?
   Sorry, the trains can not run slower. Otherwise they would occasionally loose power on turnouts or old rails. This would block the layout.

2. What about recording 30 secs MPEG and sending it to the client?
   We intend to provide inline video. We will have inline MPEG if the clients support it.

3. I get only still images.
   It's probably your browser which does not support live inline video. Video works with Netscape since version 1.1, some versions of Chimera and XMosaic. Send me a mail, if you are sure that you should get it.

4. Are the GIF stream encoder software and the modified browsers available?
   
   • The GIF stream encoder is available for ftp, but the software is under development and this is probably not the latest version.
     
   • Chimera: I'm currently talking to the author of chimera. He will probably include the modifications into his code. Version 2.0 is on the road and will be available soon.
     
   • Mosaic: A binary for Sun Solaris 2 is available for ftp.
     The source code is not yet available for ftp.

5. Will you add the inline video to Mosaic?
   I'm trying to convince the NCSA people to do the required changes in their code so that everyone can get it. We have already done it (see question #4).

6. How about a larger layout?
   The trains are already very small on the grabbed image. They would appear even smaller on a larger layout. We don't dare yet to send larger images because our intention is inline video not still images. We are thinking about a larger layout with more cameras. But our boss is not as sure as we are that the Web needs a larger layout.

7. Nothing happens. I only get the comment "And silence filled the night"?
   Are you sure you reloaded the images on the pages? If you press the reload button of Mosaic it will reload the text of the page and take old images from the cache. "And silence filled the night" is the Mosaic way of saying that the command has been sent but the server told your client to stay with this page.

8. How did you link the trains with the computer?
   The WWW server is connected via serial line /dev/ttya to the railroad controller an MSDOS PC. The PC generates Maerklin Digital commands using its 2nd serial interface.

9. IT DOES NOT WORK
   If you are sure that you reloaded the images and that no proxie/cache fools you, then the model railroad might be broken. Sometimes the trains crash into each other or loose power on old turnouts. Sometimes the controller PC hangs up. This happens more often at weekends when nobody is here to set it up again.
   If you are sure that your browser supprts any kind of inline video/animation and you get only still images, then we have to update our database about browser capabilities. Please send me a mail.

10. Video stops when starting train
    This is due to a bug in Netscape 1.1. Every HTTP request cuts server-push connections even if the HTTP response is a No Response code. Netscape should cut the connections when receiving data and not when requesting it.

11. How to make a counter
    You can always include one of the available counter services.
    Read the Access Counter FAQ or Yahoo's counter list. The shortest (own) counter I know: If you have the unix command banner:

    #!/bin/sh
    CNTFILE=/usr/local/www/httpd/logs/count
    count=`cat $CNTFILE`; count=`expr $count + 1`; echo $count > $CNTFILE
    echo Content-type: text/xbm; echo
    banner "["$count"]" | tr ' ' '+' | sed -e 's/+/0/g' | sed -e 's/#/1/g' | \
    sed -e 'p' | atobm -c 01
    

    • Save this in the cgi-scripts directory of your server. Chmod +x it.
    • Banner is available on ftp servers. There are different versions with different options and functinality, but some will work here.
    • Start with a '0' in /usr/local/www/httpd/logs/count. The count is not secure without file locking. Two acceses at the same time will sometimes reset it :-(. But a little bit more effort can make it secure.

12. How can I animate in NetScape/Mosaic?
    
    • Netscape: See the documentation of Netscape about dynamic documents.
    • Mosaic: No animations possible in Mosaic yet. However we have a modified version which supports GIF sequences and MJPEG animation. Look into our code.

13. Why can I see the trains moving (hopping) while the GIF test page shows no video ?
    We are sending the video of the trains in the format best suited for your client. This means Server-Push with JPEG for Netscape since 1.1, GIF or JPEG for other browsers, and true multi-image GIF for browsers which support it. But: The image on the multi-image GIF test page is a reference directly to the multi GIF file. This is not adapted to the browsers capabilities. Browsers which support multi-image GIF show the video. Netscape not.

14. Is it real or just some prerecorded videos ?
    Yes, it's REAL. No, it's not a fake ! There is a clock in the lower left corner.

15. Why do the pages look so bad ?
    You are probably using a HTML 2.0 WWW browser. I'm using HTML 3.0 tables to improve my layout. What you are seeing is the pure text without formatting information. I decided to do so because HTML 3.0 browsers are available since half a year and 80% of the people are using them now. I think it's time to upgrade.

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