Re: [9fans] 00E & projector

[Jack Johnson <fragment@nas.com>]

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