Intel D15343-003 - Manual (Page 112)

Intel
®
82854 Graphics Memory Controller Hub (GMCH)
112 D15343-003
5.2 DOS Compatibility Area
This compatibility region is divided into the following address regions:
• 0 - 640 kB DOS Area
• 640 - 768 kB Video Buffer Area
• 768 - 896 kB in 16-kB sections (total of eight sections) - expansion area
• 896 -960 kB in 16-kB sections (total of four sections) - extended system BIOS area
• 960 kB - 1 MB system BIOS area
There are 16 system memory segments in the compatibility area. Thirteen of the system memory
ranges can be enabled or disabled independently for both Read and Write cycles.
Figure 6. Detailed View of System Address Map
Extended
SBIOS Lower
BIOS Area ( 64
kB) 16 kB x 4
SBIOS
Upper
BIOS Area
(64 kB)
Expansion
Card
BIOS and
Buffer Area
(128 kB)
16 kBx8
Standard
PCI/ISA
Video
Memory
(SMM
Memory)
128 kB
DOS Area
PCI Memory
Range
Optional ISA
Hole
DOS
Compatibility
Memory
4 GB max
TOM
1 GB
16 MB
15 MB
1 MB
640 kB
0 B
DOS
Compatibility
Memory
0FFFFFh
0F0000h
0EFFFFh
0E0000h
0DFFFFh
0C0000h
0BFFFFh
0A0000h
09FFFFh
000000h
1 MB
960 kB
896 kB
640 kB
768 kB