[9fans] 00E & projector

[9fans] 00E & projector

[sah]

When I hook up our projector to the video
out on my TP 600E I get an interesting
result.  The screen is properly exported
to the projector all through the log
on process, but once rio kicks up I lose
the feed - presumably - and the screen
goes blue (projector driven).

Thoughts?

Sam

Re: [9fans] 00E & projector

[Russ Cox]

Are you running your screen at a higher resolution
than the projector supports?  That's what it sounds
like.  It's also possible we screwed up the CRT
code -- it doesn't get exercised much -- but usually
if you Fn-F7 to get it working before aux/vga,
it keeps working.

Re: [9fans] 00E & projector

[Sam]

It's been a while since I've tried it (we gave
up before because we didn't have time to debug
the problem), but I believe I tried several
different resolutions.  I'm preparing for a talk
in late Feb, so I'll poke at it some more and
come back with data.

Sam

On Sat, 1 Feb 2003, Russ
Cox
wrote:

> Are you running your screen at a higher resolution
> than the projector supports?  That's what it sounds
> like.  It's also possible we screwed up the CRT
> code -- it doesn't get exercised much -- but usually
> if you Fn-F7 to get it working before aux/vga,
> it keeps working.
>

Re: [9fans] 00E & projector

[Ronald G. Minnich]

On Sat, 1 Feb 2003, Russ Cox wrote:

> Are you running your screen at a higher resolution
> than the projector supports?  That's what it sounds
> like.  It's also possible we screwed up the CRT
> code -- it doesn't get exercised much -- but usually
> if you Fn-F7 to get it working before aux/vga,
> it keeps working.

Another common problem when you go to graphics mode on older thinkpads --
there is a "feature" that doesn't work with all projectors in which the
thinkpad hardware tries to autodetect external vga, and won't drive it
unless it detects it. Well, guess what, it didn't always work, as I found
at one conference where I went through three projectors and had to give up
and "talk to my slides" while the audience watched a blank screen for 45
minutes. I doubt more than 75% of them fell asleep, but I'm an optimist --
oh, no, wait, I'm not.

There was a linux utility to fix this on the 570, and I wonder if the same
problem exists on the 600. The linux utility just jammed some random magic
hardware bit and all was well (disabled the hardware mis-feature).
So it can look like a resolution problem but actually be something else.
Best bet is try 640x480 first, and if that doesn't fix it, then the
problem is something else.

ron

Re: [9fans] 00E & projector

[Sam]

The TP600E, like many laptops, has 3 modes for
display: lcd, lcd+external, and external.

I can hook up the laptop to the projector
and get a wall display - which is much farther
than I thought I'd get off the bat - but when
I toggle back to lcd display, the screen
goes an eggshell white and I lose the display
until reboot.  I see little diagonal dots
corresponding to the mouse which move about
on mouse motion.  Toggling back to external
just exports this lovely display to the wall.

Tips?

Cheers,

Sam

On Sat, 1 Feb 2003, Ronald G. Minnich wrote:

> On Sat, 1 Feb 2003, Russ Cox wrote:
>
> > Are you running your screen at a higher resolution
> > than the projector supports?  That's what it sounds
> > like.  It's also possible we screwed up the CRT
> > code -- it doesn't get exercised much -- but usually
> > if you Fn-F7 to get it working before aux/vga,
> > it keeps working.
>
> Another common problem when you go to graphics mode on older thinkpads --
> there is a "feature" that doesn't work with all projectors in which the
> thinkpad hardware tries to autodetect external vga, and won't drive it
> unless it detects it. Well, guess what, it didn't always work, as I found
> at one conference where I went through three projectors and had to give up
> and "talk to my slides" while the audience watched a blank screen for 45
> minutes. I doubt more than 75% of them fell asleep, but I'm an optimist --
> oh, no, wait, I'm not.
>
> There was a linux utility to fix this on the 570, and I wonder if the same
> problem exists on the 600. The linux utility just jammed some random magic
> hardware bit and all was well (disabled the hardware mis-feature).
> So it can look like a resolution problem but actually be something else.
> Best bet is try 640x480 first, and if that doesn't fix it, then the
> problem is something else.
>
> ron
>

Re: [9fans] 00E & projector

[Jack Johnson]

Sam wrote:
> Tips?

Sorry for the long-winded response, but I'm prone to it, and don't know
much about your scenario, so here it goes.

I deal with pseudorandom laptops and projectors a lot, and *usually* the
OS is not the main issue.  As Russ said:

>>>code -- it doesn't get exercised much -- but usually
>>>if you Fn-F7 to get it working before aux/vga,
>>>it keeps working.

Timing is the key issue.

Usually the Fn-whatever combo is a 3-way toggle: LCD, external, or both.
  With many newer laptops, it will reset the resolution of the external
device when you toggle to external-only, so it's not uncommon to find
your hardware trying to change resolution to 640x480 at an inconvenient
time.  With Windows, this usually isn't a big deal, but other OSes don't
  seem to appreciate the effort, and your sympoms are not uncommon.

The trick is to get the hardware into "both" mode before the vga kicks
in.  It's often easy to wait at a boot prompt while you cruise through
the toggle settings, and then let the machine continue to boot.

Once the screens are in sync, the OS usually doesn't know or care that
there are two monitors dangling off the same machine (Win2k/XP being
exceptions with some recent hardware).

Ron notes:
>>Another common problem when you go to graphics mode on older thinkpads --
>>there is a "feature" that doesn't work with all projectors in which the
>>thinkpad hardware tries to autodetect external vga, and won't drive it
>>unless it detects it.

This kind of goes hand in hand with the timing idea.

Some people will fire up their laptop, then either connect the external
display device while the laptop is running or while it's asleep, and the
external device never gets detected.  The 3-way toggle won't seem to
work, etc.  Besides it being just a bad idea in general to wire up a
monitor to a live machine, you will often run into the above problem,
and laptops that are prone to buggy autodetection will exhibit this
behavior even worse.

So, for review, here's the emergency drill:

	1) Turn everything off.
	2) Plug everything in.
	3) Turn on the projector.  Pop up a menu or logo screen and focus.
Make sure the thing works.
	4) Turn on the laptop and get it to pause, either at a boot prompt or
(with some models) a BIOS screen, etc.
	5) Hit the 3-way toggle until you get a display on both devices.
	6) Let the machine continue to boot normally.

With projectors that can handle the native resolution of the laptop,
I've never had a problem using the above technique.  With some older
projectors, you may run into refresh rate problems, but usually the
device will either show you a flickering or maladjusted image, or
eternally display a notice that it's still attempting to sync to the new
signal, so that kind of problem will be immediately obvious (as it
should have been if you previously saw the bootmessages being projected).

If in trouble and in doubt, always try to pick 60 or 75Hz with newer
projectors, 67Hz with really old crap.  In Plan 9, you'd want to
double-check your monitor setting in plan9.ini and potentially do some
tweaking.  If you're using monitor=lcd, it uses the xga settings and
runs at 70Hz, which should be OK for most projectors, but again will
vary with age.  You could try mulitsync65, otherwise, and then start
bumping down the resolution until you get an image (but again, only with
an older projector).

If your projector has a lower maximum resolution than your laptop
display, change the resolution of your laptop's display to match the
projector first, then power down and follow the sequence.

I have run into a very few, old laptops that won't run at less than
their native resolution.  Many years ago I remember toiling with a
laptop that would not do less than 800x600 on the LCD (other than
textmode) trying to drive a projector that wouldn't do more than
640x480.  You'd probably have to work hard to get that scenario now.

As an extreme last resort, you could always set your BIOS to acknowledge
your external video device first, configure it just like you were using
a desktop machine, and look over your shoulder during the presentation.

Good luck!

-Jack

Re: [9fans] 00E & projector

[northern snowfall]

>
>
>I toggle back to lcd display, the screen
>goes an eggshell white and I lose the display
>until reboot.  I see little diagonal dots
>corresponding to the mouse which move about
>on mouse motion.  Toggling back to external
>just exports this lovely display to the wall.
>
Ugh... be careful
Soon after this started happening on my 600E the LCD blew
completely. I have yet to find a replacement. Then again, I'm
not looking too hard (but the part number wasn't "available"
on IBM's refurbished site (or partner sites)).
Don