RE: RGB to.....?

["Keith Doxey" <ukha@xxxxxxxxxxx>]

Hi Tony,

> > If ya wanna grumble about anything being non-standard then
> > really it's a VGA input that can *TAKE* 15kHz interlaced that
> > is not "normal". :-P
>
> That's wot I was wondering - why did they do this?
>

Multisync Monitors (monitors that can accept a wide range of frequencies)
are a relatively new thing. Because a CRT uses a magnetic field to deflect
the electron beam there are scan coils around the neck of the CRT. The
impedance of a coil will change with frequency and as a result, so will the
current flowing through it. If you have ever heard a monitor click as it
changes from one resolution to another its because is is switching to
different circuitry
to accomodate the scan frequency safely.

If you were to connect a modern PC to a very old monitor and the Monitor
settings for the graphics card were set to a resolution that was too high
there would probably be some very undesireable effects on the monitor, at
worst it would go BANG!!!

Thankfully modern monitors are microprocessor controlled and display a
message saying that the signal is out of range.


> > Because the Yanks have no idea what RGB and SCART are - they
> > have had DVD players with component video outputs for a few
> > years whereas component video here really was only a
> > broadcasters tool.
>
> I wish *we* had no idea what SCART was either m8 :/
>

The functionality offered by SCART is great, its just the physical
connector
that leaves something to be desired. Most SCART problems occur because the
connector is non-locking and the thick cables put a lot of strain on the
connector which will either partially come out of its socket or at worst,
break the tracks on the PCB. If you provide strain relief by cable tying
the
cable sheath to the TV stand etc then you will avoud most of the problems.

My main gripes agains SCART are

1. they used the same connector for in/out but you can only ever do that
for
Composite Video because RGB/S-Video use the SAME Pins for In and Out so a
higher quality signal can only ever be unidirectional.

2. S-Video capability was added after the original spec as was Widescreen.
Widescreen switching was enabled by redefining the function of Pin8 to be
Tri-Level for Off/Wide/Full but there is no provision for indicating that a
signal is S-Video whereas RGB does this using Pin 16

3. Input and Output should have been separate connectors preferably male
and
female D type or similar so that they would have a suitable means of
restraint.

Keith