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On Thursday 13 December 2001 6:50 pm, you wrote: > > Can anyone adequately explain the significance of the "vga=" > > line? I mean I've read what it is suppose to do, but can anyone > > explain what it really does. > > What it enables you to do is select a video mode for your console that > will give you more than the standard 80x24 chars. I use it on my laptop > to make the console use more of the screen than a little square in the > middle (not that it makes that much difference). There is a complex calculation that allows you to construct a value for vga= from hexadecimal and it was covered (briefly) in Linux Format a while back. LXF17 Aug 2001 p20 In answer to a question about a lack of Tux at the login screen (init 3, presumably) <quote> The penguin [only shows] if you are running the console using the frame buffer even if you've got [framebuffer] support compiled in, you have to tell [the kernel] to use it. This is in the form of a vga= extension, the values of which are listed within the framebuffer configuration within the kernel source tree. </quote> http://www.linuxdoc.org/HOWTO/Framebuffer-HOWTO-5.html#ss5.1 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) (this may not render well in email, try copying into an HTML page or wait for it to turn up on the archive which uses a monospace font for message bodies) 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. 0x300 = 768 0x301 = 769 0x302 = 770 0x303 = 771 0x305 = 773 0x307 = 775 0x310 = 784 0x311 = 785 0x312 = 786 0x313 = 787 0x314 = 788 0x315 = 789 0x316 = 790 0x317 = 791 0x318 = 792 0x319 = 793 0x31A = 794 0x31B = 795 0x31C = 796 0x31D = 797 0x31E = 798 ox31F = 799 0x161 = 353 0x162 = 354 0x163 = 355 0x164 = 356 To convert decimal into hexadecimal: http://www.ambleside.schoolzone.co.uk/ambleweb/baseconvert/baseconvert.htm Or try this one: http://www.science-ebooks.com/electronics/new_page_12.htm Converts in both directions. (the 791 for the laptop equals 0x317 which in the above table gives me the expected 1024x768 16bit that I use.) I've tried to find anything on this on my own machine but just ended up wasting my time. Where to start looking? I installed kernel-source RPM and went to the modedb.c file but I couldn't find a decent set of values for vga. At least, not in the form of a single number, whether hexadecimal or decimal. The sourceforge.net link below led to the HOWTO with the table above. Other files: /usr/share/doc/kernel-doc-2.4.8/fb/modedb.txt /usr/include/linux/fb.h /usr/share/doc/kernel-doc-2.4.8/fb/framebuffer.txt [from this framebuffer.txt file] For more specific information about the frame buffer device and its applications, please refer to the Linux-fbdev website: http://linux-fbdev.sourceforge.net/ All necessary files can be found at ftp://ftp.uni-erlangen.de/pub/Linux/LOCAL/680x0/ and on its mirrors. The latest version of fbset can be found at http://home.tvd.be/cr26864/Linux/fbdev/ Does anyone have fbset already? The example given by LXF is 800x600 in 256 colours: The kernel needs the instruction '303' for this resolution but this is hexadecimal (0x303) so the value in lilo.conf is converted to decimal, 771 in this case. It was too involved for me to remember so I stick to memorising (or backing up!) values for certain situations. My Advent laptop requires 791 because the panel only works in 1024x768 16bit. It's essential on my laptop - without it, NO setting of X will ever create any screen display. It changes the font of the initial boot up (but since Mandrake 8.1, it uses Aurora so I don't see all the start-up bumpf) and whenever I see this smaller font in use, I know X will fire up. So far, each distro I've tried on the laptop has OVERRIDDEN the lilo setting and therefore X has always failed to setup first time. I've had to reboot, login and amend lilo, reboot and then configure X. > > If youre running X all the time I'd be tempted to just remove the vga= > line. > > Alex. vga=ask doesn't work on the laptop as it consistently refuses to offer 1024x768 16bit as an option. Even though the laptop runs X continually, X won't function without the vga=791 in /etc/lilo.conf -- Neil Williams ============= http://www.codehelp.co.uk neil@xxxxxxxxxxxxxx linux@xxxxxxxxxxxxxx neil@xxxxxxxxxxxx -- The Mailing List for the Devon & Cornwall LUG Mail majordomo@xxxxxxxxxxxx with "unsubscribe list" in the message body to unsubscribe.