Abit AX5 Instruction Booklet page 59

Introduction of BIOS
Shadowing address ranges (DC000-DFFFF Shadow):
This option allows you to decide if the memory block (BIOS) of an
interface card at the address DC000-DFFFF uses the shadow feature or not.
If you have no interface card using this memory block, don' t enable this
option.
Computer
knowledge
SHADOW
What is the SHADOW? The BIOS of standard video or
interface cards is stored in ROM, and it is often very slow.
With the Shadow feature, the CPU reads the BIOS on the
VGA card and copies it into RAM. When the CPU runs this
BIOS, the operation is speeded up.
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