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RE: M1 Arrived!

From: "Tony Havelka" <>
Date: Thu, 20 Aug 1998 10:17:20 -0500

> Initial impressions:

> some trouble getting the lens to stay pointed at my eye
> properly. I'm not sure if this is just I haven't bent
> the eyepiece arm quite right yet, or some play in the
> last joint.

Most people want to grab the eyepiece and move it so that it is in front of
the eye only to find that the eyepiece slowly drifts away.  The correct
procedure is to use the interlocking plastic conduit (IPC) to get the
eyepiece within +/- 2 degrees and THEN move the eyepiece for fine tuning.
The IPC flex arm was designed to take the brunt of the twisting and
torqueing that occurs.  You'll find that if you manipulate the IPC you will
not encounter any "drift" of the eyepiece over time.

> I have two complaints, that might be pilot error problems:
> 1) the image does not seem to adjust downward completely in the
> viewpiece I can adjust L<->R ok, but there is a significant band
> of viewing area that the screen image does not cover.

What type of signal are you running to the M1?  VGA or NTSC?

> 2) I can't seem to see the bottom edge of the screen image - where the
> 	task bar is in fvm95 on my monitor.  I'll check tonight to see
> 	if this is just a contrast problem

If you are running VGA check the resolution settings. Should be 640x480, 256
color.

> And one caveat to a user - if you have the image adjusted to the left
> too much, you lose the sync or something - it gets garbled.  I spent 15
minutes
> playing with it until I shifted the image right, and things cleared up
> (Tony, this might be something to either note in the troubleshooting
> guide, or even fix by a minor pan right at powerup?)

Interesting... the reason why it gets garbled is that you have panned beyond
the 1st 21 lines of the video signal (the sync area) and into the video
area.  Once in this area there is no sync available and the picture cannot
be decoded.  This is a unique problem usually only occurring in NTSC
scenarios.  Since NTSC is a loosely adhered to standard, we have encountered
many iterations on the common theme.  In an analog world, these differences
are tolerated as they only show up as "snow".  In the digital world, which
the M1 lives in, deviations off the norm may cause problems.

UNDOCUMENTED FEATURE: <the following is a service provided buy the technical
support staff at Liquid Image.  Use of the following instructions are at
your own risk as they are not formally supported.> There is a potentiometer
in the control box that adjusts the envelope of the phase lock loop +/- 40%
approximately.  This allows for accommodation of major deviations in the
NTSC signal without experiencing a "garbled" image.  By fine tuning the M1
via this pot, you can customize the acceptance/tolerance envelope of the
NTSC decoding circuit.

- Tony

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