Setting/changing Color Depth

Kjellinux · 2024-09-03 15:48

I have instaled 32 bit Q4OS on a 25 year old IBM ThinkPad 600X. After a fresh new install Color Depth is 16. To run the presentation program sent from suckless.org, I need to have Color Depth set to 24. Where and how, if at all possible, can I set Color Depth to 24?

hchiper · 2024-09-03 17:20

From what I can read on Wikipedia about your IBM ThinkPad 600X, it has 2 MB video RAM, which is short for a resolution of 1024 * 768 @ 24 bpp (1024 * 768 * 3 bytes = 2 359 296 bytes = 2,25 MB). If you are working at this maximum resolution, try to decrease to 800 * 600.

Kjellinux · 2024-09-03 17:30

From what I have been told, and from how I interpret the "Video Controller" column, the 600X has 4MB video RAM. It's still an interesting ide, regardless, to decrease the resolution to see if it changes anything.

hchiper · 2024-09-03 17:43

You're right, I forgot the 'X'. My mistake.

Kjellinux · 2024-09-03 17:48

I tried lowering the resolution, first to 800 x 600, then to 640 x 480, but no change. Color Depth stayed at 16. So, the original question remains, where and how, if at all possible, can I set Color Depth to 24?

bin · 2024-09-04 06:27

You might want to try creating xorg.conf like this:-

Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
DefaultDepth 24
Modes "1024x768"
EndSection

It needs to go in
/etc/X11/xorg.conf.d/

This assumes the native resolution is 1024x768

No guarantee but worth a try.

Kjellinux · 2024-09-04 09:49

bin wrote:

You might want to try creating xorg.conf

But definitely worth a try.

Could it possibly be that your suggestion comes from a reddit article? I think it's ment as a template where you should substitute what's between the exclamation marks with whatever is used on your specific computer. Remains to identify exactly what to substitute the template's phrases with.

Last edited by Kjellinux (2024-09-04 10:02)

Attachments:

loginscreen1.png, Size: 150.16 KiB, Downloads: 38

Kjellinux · 2024-09-07 14:35

It's been som time since I last posted. This does not in any way mean that I've been inactive. I have sought help in 4 different forums.

antiX-forum
thinkpads.com Support Community
LinuxQuestions.org
Q4OS Forum

I have tried countless ways to set Color Depth to 24, but so far without success. I have tried another distribution, Q4OS, I have created a large number of configuration files with varying content and different names placed in different directories. I have tried countless search phrases on Google to find the right information. I have read countless articles.

One article in particular, How to set desktop color depth?, has convinced me that it should be possible to set Color Depth to 24. Using xdpyinfo produced the result below (I left out a large number of repetitions at the end). In particular, i think the following part suggests that it should be possible.

supported pixmap formats:
    depth 1, bits_per_pixel 1, scanline_pad 32
    depth 4, bits_per_pixel 8, scanline_pad 32
    depth 8, bits_per_pixel 8, scanline_pad 32
    depth 15, bits_per_pixel 16, scanline_pad 32
    depth 16, bits_per_pixel 16, scanline_pad 32
    depth 24, bits_per_pixel 32, scanline_pad 32
    depth 32, bits_per_pixel 32, scanline_pad 32

One possible obstacle could be limitations in the hardware. According to Wikipedia on IBM ThinkPad 600 the IBM ThinkPad 600X Video Controller has 4 MB video memory. Even if, as the output from xdpyinfo suggests, Color Depth 24 uses 32 bits per pixel, the video memory should be sufficient (1024 * 768 * 32 bits per pixel / 8 bits per byte = 3,145,728 bytes, which is still below 4MB). It's been suggested that the there could be limitations in the actual LCD. I have run hwinfo with various hardware item options, including none at all, and searched through the output using grep with various options and search terms like "monitor", "LCD", "display", etc. without finding any information on the LCD.

Regardless of possible limitations of the hardware, the present value of the Color Depth, 16, must be set in some way, at som point in the start up process. There must be a line of code, a command, or something else, somewhere, in some file, in some directory where it takes place. I have made countless attempts to find this point, but so far without success. It can't happen all by itself, so the point must exist. Unfortunately, my lack of skills have prevented me from finding it so far. I find it very confusing that there are so many terms used that can refer to the actual display that I look at when I'm using the computer.

My hope now is that someone much more skilled than me will read the information I've put togeter and realize that "I know that" and share that knowledge.

Beginning of output from xdpyinfo:

xdpyinfo

name of display:    :0.0
version number:    11.0
vendor string:    The X.Org Foundation
vendor release number:    12101007
X.Org version: 1.21.1.7
maximum request size:  16777212 bytes
motion buffer size:  256
bitmap unit, bit order, padding:    32, LSBFirst, 32
image byte order:    LSBFirst
number of supported pixmap formats:    7
supported pixmap formats:
    depth 1, bits_per_pixel 1, scanline_pad 32
    depth 4, bits_per_pixel 8, scanline_pad 32
    depth 8, bits_per_pixel 8, scanline_pad 32
    depth 15, bits_per_pixel 16, scanline_pad 32
    depth 16, bits_per_pixel 16, scanline_pad 32
    depth 24, bits_per_pixel 32, scanline_pad 32
    depth 32, bits_per_pixel 32, scanline_pad 32
keycode range:    minimum 8, maximum 255
focus:  window 0x2200004, revert to None
number of extensions:    27
    BIG-REQUESTS
    Composite
    DAMAGE
    DOUBLE-BUFFER
    DPMS
    DRI2
    GLX
    Generic Event Extension
    MIT-SCREEN-SAVER
    MIT-SHM
    Present
    RANDR
    RECORD
    RENDER
    SECURITY
    SHAPE
    SYNC
    X-Resource
    XC-MISC
    XFIXES
    XFree86-DGA
    XFree86-VidModeExtension
    XINERAMA
    XInputExtension
    XKEYBOARD
    XTEST
    XVideo
default screen number:    0
number of screens:    1

screen #0:
  dimensions:    1024x768 pixels (271x203 millimeters)
  resolution:    96x96 dots per inch
  depths (7):    16, 1, 4, 8, 15, 24, 32
  root window id:    0x400
  depth of root window:    16 planes
  number of colormaps:    minimum 1, maximum 1
  default colormap:    0x20
  default number of colormap cells:    64
  preallocated pixels:    black 0, white 65535
  options:    backing-store WHEN MAPPED, save-unders NO
  largest cursor:    1024x768
  current input event mask:    0xfa200f
    KeyPressMask             KeyReleaseMask           ButtonPressMask          
    ButtonReleaseMask        ButtonMotionMask         StructureNotifyMask      
    SubstructureNotifyMask   SubstructureRedirectMask FocusChangeMask          
    PropertyChangeMask       ColormapChangeMask       
  number of visuals:    120
  default visual id:  0x21
  visual:
    visual id:    0x21
    class:    TrueColor
    depth:    16 planes
    available colormap entries:    64 per subfield
    red, green, blue masks:    0xf800, 0x7e0, 0x1f
    significant bits in color specification:    6 bits
  visual:
    visual id:    0x389
    class:    TrueColor
    depth:    16 planes
    available colormap entries:    64 per subfield
    red, green, blue masks:    0xf800, 0x7e0, 0x1f
    significant bits in color specification:    6 bits
...

crosscourt · 2024-09-07 18:52

Your laptop uses the Neomagic NM2360 4mb sgram agp video controller. Its definitely supported in Xorg but there appears to be some issues with the drivers for some users. There also seems to be issues with the NM2070 video controller that does not support 24bit even though the driver does. It would depend on which video controller you actually have and whether that driver is interacting correctly with that device.
Be aware that many NM 2360 users haven't been able to use 24bit so there may be something more to this situation that we may not find out.

Heres a site that shows some specifics about the hardware, https://Linux.die.net/man/4/neomagic

If you can determine what the specific hardware you have, as there are more variations of the 600x than I even realized it may determine whether 24bit is possible. Driver options are limited and making changes manually may not necessarily work.

Last edited by crosscourt (2024-09-07 18:57)

Kjellinux · 2024-09-07 22:07

@crosscourt

That's very interesting information. I will definitely dig deeper into it in the next few days.

Q4OS Forum

#1 2024-09-03 15:48

Setting/changing Color Depth

#2 2024-09-03 17:20

Re: Setting/changing Color Depth

#3 2024-09-03 17:30

Re: Setting/changing Color Depth

#4 2024-09-03 17:43

Re: Setting/changing Color Depth

#5 2024-09-03 17:48

Re: Setting/changing Color Depth

#6 2024-09-04 06:27

Re: Setting/changing Color Depth

#7 2024-09-04 09:49

Re: Setting/changing Color Depth

#8 2024-09-07 14:35

Re: Setting/changing Color Depth

#9 2024-09-07 18:52

Re: Setting/changing Color Depth

#10 2024-09-07 22:07

Re: Setting/changing Color Depth

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