Filesystems on tape and Videotapeing

[Knobi der Rechnerschrat]

Hello Netlanders,

  I've got two problems:

1) This was sent by a colleague of mine some weeks ago and never
   answered. We want to create a filesystem on the 1/4" cartridge
   tape and mount it into our system (3130 or 4D/70G). The questions
   are: a) is it possible at all? and
        b) if (answer_a == yes) How to do it ???

   Please don't send comments on how silly it is to attempt such
   a task. We just have reasons (even if it's pure curiosity).

2) I want to contribute to the videotaping debate on this list. We
   have the following scenario: a 4D/70GT without GENLOCK device,
   a RGBS -> composite-video converter, a UMATIC-low-band recorder
   recognizing PAL (European Video Standard) signals. Now we see
   some problems:

   - on the GT we have a colour shift from the left to the right of the
     screen. I suspect this is a subcarrier problem. Due to the lack of
     a GENLOCK for the GT I can't adjust that with my equipment (we  can
     correct it with our recorder, but then every other signal gets
     recorded with a shift). On a 4D/70G (also without GENLOCK) everything
     works ok. So, what are the differences between the G and GT style
     PAL signals ?

   - Our second problem is a bit harder for us. We have an animation
     program that displays a scene in front of  a goraud shaded background.
     The color-map for the background is 256-entries deep and nonlinear
     build (thats not so important). During the animation we have a
     sequence of 200 frames where we change the complete background
     color map for every frame (that might be clumsy, but thats the
     way it was done: quick, dirty and it works fine). With the 60HZ
     screen we have no problems, everything is fine. Now we change to
     setmonitor(PAL). As soon as we arrive at the scene changing the
     background, our problems start. The color map is simply inccorrectly
     changed (which we can check by using 'showmap'). It seems that
     changing color-maps in PAL mode takes a VERY long time. Is that
     observation correct and are there any chances to get that changed?

3) A third problem related to color-maps: On the G and GT machines
   loading  color-maps seems to be slow (even in HZ60-mode). Again,
   is that observation correct, and are there any plans to change
   that?

Regards
Martin Knoblauch

TH-Darmstadt
Dept. Physical Chemistry 1
Petersenstrasse 20
D-6100 Darmstadt
West-Germany

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