NEC Versa LX, Service And Reference Manual

Page: 124 / 138

Specifications 9-13
Memory Map
The system supports system and video shadowing, both controlled through
complementary metal oxide semiconductor (CMOS). The system supports BIOS
as a cacheable area with write protection. The following table shows the
system's memory map.
System Memory Map
Memory
Space
Size Function
000000-
0002FFh 768
bytes BIOS Interrupt Vector Table
000300-
0003FFh 256
bytes BIOS Stack Area
000400-
0004FFh 256
bytes BIOS Data Area
000500-
09FFFFh 639 KB Applications Memory (used by the O/S, device drivers, TSRs, and all
DOS applications
0A0000-
0AFFFFh 64 KB Video Buffer (EGA and VGA)
0B0000-
0B7FFFh 32 KB Video Buffer (monochrome, CGA color, VGA monochrome)
0B8000-
0BFFFFh 32 KB Video Buffer (CGA, EGA color, and VGA color)
0C0000-
0CBFFFh 64 KB Video ROM (EGA and VGA)
0D0000-
0DFFFFh 64 KB Used by Adapter ROMs (i.e., network controllers, hard disk controllers,
SCSI host adapters)
0E0000-
0EFFFFh 64 KB Used by System ROM adapters (i.e., network controllers with boot
capability)
0F0000h-
0FFFFFh 64 KB System AMIBIOS (includes Setup and hard disk drive utilities)
100000h-
1FFFFFF (non-
AGP)
100000h-
3FFFFFF
(AGP)
32 MB
(non-
AGP)
64 MB
(AGP)
Built-In Extended Memory
2000000-
5FFFFFF (non-
AGP)
4000000-
FFFFFFF
(AGP)
up to
256 MB
(both) Extended Memory