I wish I know the answer, it seems that many people have similar problem with Xfree86, my Philips 15" LCD is capable of 1024x768, but I can only get 800x600, also the same problem on a Sony LCD, but some other made worked fine.
I used cheatcode screen=1280x1024 in Knoppix 3.7, 3.8, and 3.8.1 but it only sets max resolution at 1152x864 in the control panel.
How do I get it to work correctly?
I wish I know the answer, it seems that many people have similar problem with Xfree86, my Philips 15" LCD is capable of 1024x768, but I can only get 800x600, also the same problem on a Sony LCD, but some other made worked fine.
I had the same problem with a Dell Optiplex until I went into the BIOS and set the video memory to 8Mb. Is there a way to set the colors to 64 bit with knoppix? I tried the cheatcode depth=64 but it didn't seem to make a difference.
methinx the cheat code will apply to the tty screens.
the desktop is still controlled by KDS and you need to
su kxconfig
to make sure the detected hardware is what you need it to be.
my i815 is only detected as generic 810
O boy you are God sent what a relief !!! most people struggling with the XF86Config but forgot about the kxconfig. I finally got it right, I see that kxconfig will modify the XF86 config file, and by setting the default depth to 24 or more the screen looks great. But I am still wondering why my display card and LCD was detected properly during boot up, but it won't install and force to use standard VGA that's causes the problem.

SFP TO RJ45 TRANSCEIVER SFP MODULE COPPER SFP OPTICAL PORT TO RJ45 ETHERNET PORT
$7.99
Dell Intel X710-DA2 5N7Y5 Dual-Port 10GbE SFP+ PCIe 3.0 x8 Network Adapter
$27.50
Cisco Acacia DP04QSDD-E25-840 400G QSFP-DD Coherent DCO Transceiver Module
$699.99
NEW Sealed Cisco SFP-10G-LR 10GBASE-LR SFP+ 1310nm 10km *US Shipping*
$24.00
Genuine Cisco SFP-10G-SR 0-2415-03 10 Gigabit Transceiver
$5.40
Intel X520-DA2 10Gb 10Gbe 10 Gigabit Network Adapter NIC Dual Port E10G42BTDA
$28.94
HP 560SFP+ 10GB 2-port PCIe NIC Ethernet ADAPTER 669279-001 w/ (2) 10GB SFP+
$16.99
Lot of 5 Cisco 10G SFP+ 850nm 300m Transceiver Module P/N: SFP-10G-SR-10-2415-03
$15.00
Dell 10 Gigabit SFP+ SR Transceiver 0XYD50 NEW SEALED
$24.99
Arista SFP-10G-SR 10GBASE-SR XVR-10001-20 850nm SFP+ Optical Transceiver
$30.00