Re: Psychophysics Windows 2.5

1
Aaron Johnson wrote:

>
> I've got a small problem (almost trivial) concerning the new version
> of Psychophysics Toolbox 2.5. I'm running on Windows XP Professional
> using Matlab 6.1.
>
> In order to run under 256 colors, in XP you need to modify the desktop
> shortcut to Matlab, and change the compatibility to let the display
> run in 256 colors.

I have no experience with Windows XP. So just to make sure that I
understand correctly: Windows XP by default prohibits applications from
using 256-color mode, even though the hardware supports it ? An
application must be granted a concession to use 8-bit mode by modifying
a shortcut which points to the application ? Strange. I would guess
that Microsoft did that to maintain a minimum standard of appearance on
the desktop.

> For the first time through the demos it runs fine. However, when the
> SCREEN('CloseAll'); command is called at the end of the demo programs,
> it reverts back to the native screen color settings. Since Windows XP
> doesn't have an option to keep the screen colors at 256 permanently
> (only choices are 16- and 32-bit color), I've been trying to find a
> fix to prevent having to re-boot matlab each time you run a stimulus.
> Any suggestions?

I am confused about what is the interaction between the settings in the
shortcut and the default desktop settings. When you make changes to the
shortcut and then launch Matlab, does the Windows desktop switch to
256-color mode ? Or instead do the changes made to Matlab shortcut
just set a permission flag, which then allows a Matlab process to change
the display mode to 256-colors.

Best,

Allen

PS. I am copying this to the Psychtoolbox forum to inform others.



Aaron Johnson wrote:

>
> Hi Allen,
>
> I've got a small problem (almost trivial) concerning the new version
> of Psychophysics Toolbox 2.5. I'm running on Windows XP Professional
> using Matlab 6.1.
>
> In order to run under 256 colors, in XP you need to modify the desktop
> shortcut to Matlab, and change the compatibility to let the display
> run in 256 colors. For the first time through the demos it runs fine.
> However, when the SCREEN('CloseAll'); command is called at the end of
> the demo programs, it reverts back to the native screen color
> settings. Since Windows XP doesn't have an option to keep the screen
> colors at 256 permanently (only choices are 16- and 32-bit color),
> I've been trying to find a fix to prevent having to re-boot matlab
> each time you run a stimulus. Any suggestions?
>
> tiaraidh an drasda
>
> Aaron
> ______________________________________________________________
>
> Aaron Johnson
> McGill Vision Research Unit
> Department of Ophthalmology
> 687 Pine Avenue West, Rm. H4-14,
> Montreal, Quebec,
> Canada
> H3A 1A1
>
> Tel. (514) 842 1231 Ext. 34819
> Fax: (514) 843 1691
> email: aaron.johnson1@...
> http://ego.psych.mcgill.ca/labs/mvr/Aaron/index.html
> ______________________________________________________________
>
2
Aaron Johnson wrote:

>
> From the Windows Help:
> Some games and other software programs /require/ that your monitor be
> set to colors, or they run better in colors. Many of those programs
> will switch your monitor to colors automatically when you start the
> program. For those that don't...

Aaron,

SCREEN should set the bitdepth by itself. It falls into the "programs
will switch your monitor to colors automatically " category. It
shouldn't need any help from the XP "Run in colors" check box. The
pixelSize argument to 'OpenWindow' sets the pixel size.

What does ScreenDemo do if you don't use the XP "Run in colors" checkbox. ?

Best,

Allen