[ltp] 15" DisplaySize (DPI value)

Noah Dain linux-thinkpad@linux-thinkpad.org
Thu, 16 Mar 2006 14:39:15 -0500


On 3/16/06, noc ops <aptgetd@gmail.com> wrote:
>
> Peter Fr=FChberger wrote:
> > noc ops schrieb:
> >
> >>>Based on the below formula my DPI value doesn't appear to be making
> >>>sense. Not sure I'm missing something.
> >>>
> >>>I would appreciate if someone could validate this value.
> >>>
> >>>
> >>>I have a laptop (15") w/ 1024x768 (max) resolution. My xdpyinfo output
> >>>displays 85x85 dpi?
> >>>
> >>>formula:
> >>>diagonal mm =3D diagonal inches * 25.4
> >>>horizontal mm =3D 4* diagonal mm / 5
> >>>vertical mm =3D 3 * diagonal mm /5
> >>>
> >>>381mm =3D 15 * 25.4
> >>>305mm =3D 4* 381mm /5
> >>>229mm =3D 3* 381mm /5
> >>>
> >>>DisplaySize =3D 305  229
> >>>
> >>>
> >>>Here's a cut&paste of my xorg.conf
> >>>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> >>>
> >>>Section "Files"
> >>>        FontPath        "/usr/share/X11/fonts/misc"
> >>>        FontPath        "/usr/share/X11/fonts/cyrillic"
> >>>        FontPath        "/usr/share/X11/fonts/100dpi/:unscaled"
> >>>        FontPath        "/usr/share/X11/fonts/75dpi/:unscaled"
> >>>        FontPath        "/usr/share/X11/fonts/Type1"
> >>>        FontPath        "/usr/share/X11/fonts/CID"
> >>>        FontPath        "/usr/share/X11/fonts/100dpi"
> >>>        FontPath        "/usr/share/X11/fonts/75dpi"
> >>>        # paths to defoma fonts
> >>>        FontPath        "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueT=
ype"
> >>>        FontPath        "/var/lib/defoma/x-ttcidfont-conf.d/dirs/CID"
> >>>EndSection
> >>>
> >>>Section "Module"
> >>>        Load    "GLcore"
> >>>        Load    "i2c"
> >>>        Load    "bitmap"
> >>>        Load    "ddc"
> >>>        Load    "dri"
> >>>        Load    "extmod"
> >>>        Load    "freetype"
> >>>        Load    "glx"
> >>>        Load    "int10"
> >>>        Load    "type1"
> >>>        Load    "vbe"
> >>>EndSection
> >>>
> >>>{snip}
> >>> ......
> >>>
> >>>Section "Device"
> >>>        Identifier      "ATI Technologies, Inc. Radeon 330M/340M/350M
> >>>(RS200 IGP)"
> >>>        Driver          "ati"
> >>>        BusID           "PCI:1:5:0"
> >>>EndSection
> >>>
> >>>Section "Monitor"
> >>>        Identifier      "Generic Monitor"
> >>>        Option          "DPMS"
> >>>        DisplaySize     305     229
> >>>EndSection
> >>>
> >>>Section "Screen"
> >>>        Identifier      "Default Screen"
> >>>        Device          "ATI Technologies, Inc. Radeon 330M/340M/350M
> >>>(RS200 IGP)"
> >>>        Monitor         "Generic Monitor"
> >>>        DefaultDepth    24
> >>>        SubSection "Display"
> >>>                Depth           1
> >>>                Modes           "1024x768"
> >>>        EndSubSection
> >>>        SubSection "Display"
> >>>                Depth           4
> >>>                Modes           "1024x768"
> >>>        EndSubSection
> >>>        SubSection "Display"
> >>>                Depth           8
> >>>                Modes           "1024x768"
> >>>        EndSubSection
> >>>        SubSection "Display"
> >>>                Depth           15
> >>>                Modes           "1024x768"
> >>>        EndSubSection
> >>>        SubSection "Display"
> >>>                Depth           16
> >>>                Modes           "1024x768"
> >>>        EndSubSection
> >>>        SubSection "Display"
> >>>                Depth           24
> >>>                Modes           "1024x768"
> >>>        EndSubSection
> >>>EndSection
> >>>
> >>>Section "ServerLayout"
> >>>        Identifier      "Default Layout"
> >>>        Screen          "Default Screen"
> >>>        InputDevice     "Generic Keyboard"
> >>>        InputDevice     "Configured Mouse"
> >>>        InputDevice     "Synaptics Touchpad"
> >>>EndSection
> >>>
> >>>Section "DRI"
> >>>        Mode    0666
> >>>EndSection
> >>>
> >>>
> >>>Any insight will be appreciated.
> >>>
> >>>
> >>>
> >>>regards,
> >>>/virendra
> >>>
> >
> >
> > seems to be correct, I use the same values!
> > fritsch@todesstern:~$ less /var/log/Xorg.0.log |grep DPI
> > (**) RADEON(0): DPI set to (85, 85)
> >
> > fritsch@todesstern:~$ cat /etc/X11/xorg.conf  |grep DisplaySize
> >         DisplaySize     305 229
> ------------
> Thanks. I also ran through another calc to confirm the same.
>
> 1204*25.4/85 =3D 305
> 768*25.4/85 =3D 229
>
>
> >
> > I stil cannot belive that you shipped back your 1400x1050 Display :-(
> ------------
> I just found out that IBM will be shipping me a replacement :-)
>
> So yes now I will have a chance to test/confirm 1400x1050 output what
> others have claimed.
>
>
>
> regards,
> /virendra
>
> >
> > Regards,
> >
> > Peter
> >
> >
> > --
> >                   Key-ID:     0x1A995A9B
> >                   keyserver: pgp.mit.edu
> > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> > Fingerprint: 4606 DA19 EC2E 9A0B 0157  C81B DA07 CF63 1A99 5A9B
> --
> The linux-thinkpad mailing list home page is at:
> http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad
>

same numbers here, pretty much.

I have a 15 inch screen and run it at 1400x1050.  After much gnashing
of teeth and restarting of X11, I came to these entries for xorg.conf
(ubuntu, but should be the same):

Section "Monitor"
    Identifier  "Generic Monitor"
    Option      "DPMS"
    ## actual size: 304.8mm x 228.6mm
    DisplaySize 304 228
EndSection

and xdpy gives me:
  screen #0:
    dimensions:    1400x1050 pixels (307x230 millimeters)
    resolution:    116x116 dots per inch

these by far look the best here, using a mix of bitstream vera and
microsoft web fonts, vera looking better overall of course.

--
Noah Dain
"Single failures can occur for a variety of reasons that have nothing
to do with a hardware defect, such as cosmic radiation ..." - IBM
Thinkpad R40 maintenance manual, page 25