[ltp] X60 produces fuzzy VGA output in high resolutions - will Ultrabase help?

[Shot (Piotr Szotkowski)]

--YkJPYEFdoxh/AXLE
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

Richard Neill:

> Shot (Piotr Szotkowski) wrote:

>> I=E2=80=99m connecting my X60 to an external LCD, and the higher the res=
olution=20
>> the image gets fuzzier =E2=80=93 if I stay at a resolution with a 75 Hz =
refresh=20
>> rate the quality is quite good, but if I go all the way to 1680=C3=97105=
0 px=20
>> the refresh rate drops to 60 Hz (or maybe 50 Hz, I can=E2=80=99t check a=
t the =20
>> moment) and my external screen looks a bit fuzzy, much worse than the =
=20
>> internal 1024=C3=97768 px screen. Changing the clock phase setting on my=
 LCD=20
>> makes this a bit more bearable, but not much.

> Are you sure you're running at the right resolution?

Yes. I can=E2=80=99t stand LCD rescaling, so if I=E2=80=99m running the LCD=
 in a lower=20
resolution than the display=E2=80=99s max, I just use the setting that makes
it keep 1-to-1 pixel mapping and add a black frame (the lower the=20
resolution the larger the frame).

This is actually what prompted me to the real problem: if I=E2=80=99m runni=
ng
in lower resolutions (like 1024=C3=97768 at 75 Hz), the image is very good,=
=20
but when I up the resolution, every time the refresh rate diminishes,=20
the image is more fuzzy (it=E2=80=99s exactly of the same fuzziness at two=
=20
resolutions with the same refresh rate).

And it=E2=80=99s not fuzzy in a way that rescaled image is fuzzy, it=E2=80=
=99s way more=20
subtle; you can perfectly make individual pixels, it=E2=80=99s just that th=
eir=20
edges are a little bit out of focus (compared to the internal LCD, which=20
is totally sharp, or the same external LCD in higher refresh rates,=20
i.e., lower resolutions).

> You might also check your cable setup - if you see ghosting=20
> (typically, edges appear to "echo" faintly a few cm to the right)=20
> - you need to use a better VGA cable. Importantly, you should only
> use 1 VGA lead, and never join them, as you get reflections from the=20
> impedance mismatch at the connectors.

It=E2=80=99s not ghosting, though. My LCD (Eizo S2031W) can scan the signal=
 it=20
receives over the analogue input and try to match the proper phase and=20
clock, and it makes much, much better job at it the higher the refresh=20
rate =E2=80=93 that=E2=80=99s why it works so well with 75 Hz resolutions a=
nd so bad=20
with 60 Hz ones. I tried setting the phase by hand, but the auto sync=20
usually chooses the best one (and the image is fuzzy anyway).

It=E2=80=99s best seen on a 1=C3=972 px black-and-white =E2=80=98checkers=
=E2=80=99 =E2=80=93 the image even=20
=E2=80=98floats=E2=80=99 in lower refresh rates when the disk is active (mu=
ch like the=20
TV image =E2=80=98floated=E2=80=99 a bit sometimes when it was on air anten=
ne in my=20
childhood years).

> You might also consider a USB-DVI adapter.

I was wondering about this option. Will it work with the Intel
graphics in X60, and will it work under Linux (Ubuntu in my case)?

I remember looking at these adapters and then ruled them out for some=20
reason, and I=E2=80=99m not sure whether it wasn=E2=80=99t because of the g=
raphic=20
chipset =E2=80=93 note that ultrabases for ATI/nVidia-equipped laptops have
DVI outputs, while the X6 does not =E2=80=93 and this might be because the =
Intel=20
chipset is not able to output digital signal for some reason.

> As for the ultrabase, it won't help you. The VGA
> part of the ultrabase is just a pass-through port.

I vaguely remember reading somewhere that the analogue signal at the=20
ultrabase=E2=80=99s VGA output is of higher quality that the one from the=
=20
internal port =E2=80=93 even though they both are originating from the same=
=20
chipset. (It=E2=80=99s so irritating that I can=E2=80=99t simply get an X6 =
and check=E2=80=A6)

> Lastly, the refresh rate for an LCD shouldn't matter too much.
> (Unless you're a gamer and really care about pixel response times).=20
> Refresh-rate mattered with CRTs to reduce flicker, but LCDs don't=20
> flicker anyway.

Yeah, and usually the LCD screen refreshes less often than the
lower refresh rate anyway. I know the theory, but I see what
I see; apparently, the quality of the signal from the VGA port
at the lower refresh rates (higher resolutions) is so much worse
that my LCD=E2=80=99s analogue-to-digital converter can=E2=80=99t make the =
same=20
conversion from it.

My reasoning for trying the ultrabase is the below:

1. The cable is ok, as the image is clear at higher refresh rates.
2. The chipset is ok, as it can produce images at 1600=C3=971050 px.
3. So, maybe, the flaw is in the internal VGA port, and if I used
   an external one the image would be clear at 60 Hz as well.

(I can see that 1. might not be true, though.)

If only the X6 wasn=E2=80=99t so expensive (especially for a glorified
digital-to-analogue converter=E2=80=A6), or was equpped with a DVI port=E2=
=80=A6

Thanks a lot for your reply!

=E2=80=94 Shot
--=20
>> The Ruby community should proceed with all deliberate
>> speed towards ISO standardization of the language.
> Yeah, look what it did to Forth.
Don=E2=80=99t just say it, show it. http://vividpicture.com/aleks/atari/for=
th.jpg
        [M. Edward (Ed) Borasky, Matt Lawrence, Gregory Brown, ruby-talk]

--YkJPYEFdoxh/AXLE
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: Digital signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)

iEYEARECAAYFAknaKZgACgkQi/mCfdEo8Ur1yQCgliXfd+yhcn8DIG1C7r9X6Qsp
bAYAn278cU28mjHIhyp635Nz7Vd19YDY
=ZuOT
-----END PGP SIGNATURE-----

--YkJPYEFdoxh/AXLE--