Appendix
MEMORY MAP
The following table shows the use of the fiirst megabyte of
memory.
Codes
Length
000000 - 0002 FFh
768 bytes
000300 - 0003FFh
256 bytes
000400 - 0004FFh
256 bytes
000500 - 09FFFFh
640 KB
OAOOOO - OBFFFFh
1 28 KB
OBOOOO - OB7FFFFh
32 KB
OB8000 - OBFFFFh
32 KB
OCOOOO - OC7FFFh
32 KB
OC8000 - OCFFFFh
32 KB
ODOOOO - ODFFFFh
64 KB
OEOOOO - OEFFFFh
64 KB
OFOOOO - OFFFFFh
64 KB
•
52 User's Manual
Description
BIOS lntenupt Vector Table
BIOS Stack Area
BIOS Data Area
Applications Memory, used by the operating system,
device drivers, TSRs, and all DOS applications.
Video Buffer (EGA and VGA)
Video Buffer (for Monochrome, CGA color, and
VGA monochrome).
Video Buffer (for CGA, EGA color, and VGA color).
Video ROM (EGA and VGA)
Unused. Reserved for Adaptor ROMs (other devices
requiring ROMs).
Used by Adaptor ROMs, such as Network
Controllers, Hard Disk Controllers, and SCSI Host
Adaptors.
Used by System ROM, which can include Network
Controllers with boot-up capabilities, and other
devices. lfthe system BIOS is 1 28KB in length (an
EISA BIOS), the first 64KB ofROM is here.
System BIOS , which includes the BIOS Setup
utility and hard disk utilities.