• vmode is a program to set video resolution while in console mode. To set resolution at boot time, add these lines to /etc/rc.d/rc.local:

  
  if [ -x /sbin/vmode ]; then
     echo "Resolution set to 640x480, 16-bit depth, 67Hz" >> /etc/issue
     /sbin/vmode 6 16
    #echo "Resolution set to 1024x768, 8-bit depth, 72Hz" >> /etc/issue
    #/sbin/vmode 15 8
  fi
  

• See the Installation Guide for other vmodes.

• It is likely that not all vmodes will work with your monitor, even if those modes work in MacOS. or example, although the Apple Multiscan 17 can be set to 1024x768 and 16-bit color for the stock 6500, LinuxPPC will only accept this resolution at 8-bit. This caveat applies to resolution as well as color depth, and appears to change often with kernel builds.

• vmode appears to be broken with every kernel after 2.1.24.

• There is no vmode command in the MkLinux directory tree. MkLinux gets its monitor mode information from the last video mode used in the MacOS.

• As for LinuxPPC (see above), it is likely that not all vmodes will work with your monitor, even if those modes work in MacOS. This caveat applies to both resolution and color depth. For example, although my Apple Multiscan 17 can be set to 1024x768 and 16-bit color at 75Hz in MacOS, MkLinux will only accept this resolution if MacOS video is set beforehand at 1024x768, 16-bit, and 72Hz or 60 Hz, not 75Hz.

video=atyfb:vmode:16,cmode:16

where vmode is as described above and cmode is color depth. atyfb in this case is the video driver. As described above, even though a mode is available in MacOS does not mean that it is available in Linux.