Successful CD boot:

KNOPPIX_V3.4-2004-05-04-EN.iso

Compaq Presario 2100 Series
1.4G AMD Athlon XP-M
256M Ram (shared with vga to 192M)
30G HD, built in floppy, usb, firewire, etc

With no command line the screen goes blank immeadiately after the initail boot screen.
To boot properly, use one of the following command lines:

knoppix acpi=off noscsi
knoppix26 acpi=off noscsi

acpi causes initial blank screen/no boot.
scsi probe must be disabled to avoid is seg faulting.

KNOPPIX ROCKS!

James