Talk:Vga=xxx

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Accuracy Questioned

I have a few questions and comments.

1) I put a comment at the end a few days ago that these instructions are either incomplete or inaccurate. Specifically, I said that during my tests, step 4 had to be:

4. Add 0x20A to the hex code of the mode you want

This was deleted without explanation. I was wondering if other people could test to see if you have to add 0x20A, or if 0x200 sometimes works too. If 0x200 never works, it should be changed. If it sometimes works, the instructions should still be changed to be more universal.

One more thing. At the end of the article, it says that Xsetup needs to be run if this is the first time. Is that why vga=xxx always runs Xsetup when used from a LiveCD? IOW, the specific value has no effect when used to boot LiveCD? If so, I think it should be mentioned more clearly in this article.

edit 19/9/07 - andrewb

The value input at the boot prompt will work for a LiveCD boot. xsetup will always run (unless you have a backup stored on a hard drive or removable storage present at boot time), all you have to do is select xfbdev in xsetup, but the correct vga=xxx must have been used in order to get the resolution you want.


edit 29/11/06 - andrewb:

I authored the part including the instructions, based on a Libretto 100. For the Libretto it is 0x200 that needs to be added. 0x200 is referred to in the Linux Framebuffer HOWTO (e.g.: http://www.faqs.org/docs/Linux-HOWTO/Framebuffer-HOWTO.html) as the value to be used. The HOWTO does say that some modes are at the discretion of the manufacturer & may need some fiddling around to get working. I suggest you set up a page for your system under Specific systems (http://damnsmalllinux.org/wiki/index.php/Category:Specific_Systems) to detail particular settings for your system. I based the original text on a walkthrough using the information from the HOWTO & quoted the Libretto results purely as an example as that is what I had to hand when I wrote it. I agree that if there are different values that are commonly found in other systems then they should be listed on this page.

For reference, here is the relevant section from the HOWTO:


5.3 What VESA modes are available to me?

This really depends on the type of VESA 2.0 compliant graphic card that you have in your system, and the amount of video memory available. This is just a matter of testing which modes work best for your graphic card.

The following table shows the mode numbers you can input at the VGA prompt or for use with the LILO program. (actually these numbers are plus 0x200 to make it easier to refer to the table)

   Colours   640x400 640x480 800x600 1024x768 1152x864 1280x1024 1600x1200
   --------+--------------------------------------------------------------
    4 bits |    ?       ?     0x302      ?        ?        ?         ?
    8 bits |  0x300   0x301   0x303    0x305    0x161    0x307     0x31C
   15 bits |    ?     0x310   0x313    0x316    0x162    0x319     0x31D
   16 bits |    ?     0x311   0x314    0x317    0x163    0x31A     0x31E
   24 bits |    ?     0x312   0x315    0x318      ?      0x31B     0x31F
   32 bits |    ?       ?       ?        ?      0x164      ?

Key: 8 bits = 256 colours, 15 bits = 32,768 colours, 16 bits = 65,536 colours, 24 bits = 16.8 million colours, 32 bits - same as 24 bits, but the extra 8 bits can be used for other things, and fits perfectly with a 32 bit PCI/VLB/EISA bus.

Additional modes are at the discretion of the manufacturer, as the VESA 2.0 document only defines modes up to 0x31F. You may need to do some fiddling around to find these extra modes.


BTW - if you select the history tab on the page it will tell you who edited / deleted your comment.



Decimal

How do you convert 0x0328 to a decimal, 808? I need help --Blastinonyall 14 August 2007 04:17 (EDT)

   8 + (2 x 16) + (3 x 16 x 16) = 808 !!!