Octek HAWK 486, Manual

Page: 83 / 97

SYSTEM BIOS
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A-29
(10)SHADOW RAM CONFIGURATION
In this section, the BIOS allows you to select "shadow RAM"
function for the address in 640K to 1M region. The BIOS will detect
which address is occupied by adapter ROM and video ROM. The address
range of C0000H to CFFFFH, which is usually used by VGA and EGA
BIOS, is divided into four 16K blocks. The memory space from
D0000H to DEEEEH is also divided into four 16K blocks. The last
memory block is E0000H to EFFFFH. The BIOS ROM is resident at
F0000H and is always shadowed.
When no memory block is selected to be shadowed in the range
from D0000H to DFFFFH and E0000H to EFFFFH, these memory
blocks may be mapped to the top of memory and served as extended
memory. In this case, the memory block originally locates at A0000H to
BFFFFH where is already occupied by display memory will also be
remapped to the top of memory. There is additional 256KB available in
the extended memory.
Each adapter ROM and video ROM will be assigned a number.
If a ROM occupies more than one block, the BIOS will show the same
ROM number for each block.
To set a ROM to be shadowed, move the cursor to a particular
block and change to the "WP-Shadow". If the ROM occupies more than
one block, just set one block to be shadowed and then other blocks will
be set accordingly. It avoids the mistake that you just enable the shadow
RAM function for part of a ROM.
The address range that is not used may be available to software
by setting to "RW-Shadow". This feature is useful to many memory
management utilities and advanced operation systems. These utilities can
move the memory resident files and device drivers to these address