mirroring?

1
dear geoff

the best place to write for advice is the PsychToolbox forum.
http://psychtoolbox.org/forum.html
i'm cc-ing there now, because i think that others might share from our
interchange.

hardware mirroring (eg on your old powerbook) is simple, as you know.
from the software side there is just one device.

software mirroring (eg on your new powerbook) is a bit tricky. from the
software side there are two independent devices. you should be able to
get a screenNumber for each device and you should be able to use SCREEN
'SetClut' on each, independently. software mirroring is usually not
preferred because it's slow; the computer has to write separately to each
device.

if you apply SetClut to the correct screenNumber there should not be any
problem.

does that help?

best

denis

>Hi Dennis,
>
>I'm not sure if you're the one I should be sending a PsychToolbox question
>to. If not, ignore this message but please let me know who to contact.
>
>I have PowerBook laptop G3/400 running:
>OS 9.0.4
>Matlab version 5.2.1.1421, and
>PsychToolbox version 2.44
>
>I use an external LCD projector, and I need to have mirroring on since
>I can't view the image produced by the projector (the typical fMRI setup).
>
>The problem is that SetClut only changes the clut for the latptop screen,
>but not for the projector. I've tried lots of SCREEN preferences, but none
>seem to help.
>
>I have older PowerBook G3/300 laptop running OS 8.1 that allows me to use
>simulscan which mirrors naturally. Apparently this is because the older
>laptop only has one video driver, unlike the G3/400.
>
>Is this a bug, or am I doing something stupid?
>
>Thanks,
>
>-Geoff
2
>At 01:22 PM 04/13/2001 -0400, you wrote:
>>>If you're interested, the problem is straightforward. When software
>>>mirroring turnd on in the monitors control panel, 'PutImage' correctly
>>>inserts the same image into both video buffers, but 'SetClut' only changes
>>>the clut for the laptop's screen, not the external video buffer.
>>
>>there are still two devices there. each will have its own screenNumber.
>>setclut will affect the device associated with the right screennumber.
>>
>>apple has stuff in copybits so that copying to one screen results in
>>copying to both. they have not done anything about setclut (which is a
>>low level driver call).
>>
>>best
>>
>>denis
>OK, well there you go. It all makes sense now.
>
>Thanks.
>
>-Geoff
>
dear geoff

oh good.

best

denis