PC BIOS Memory Layout
1
00000H Interrupt Vector(256*4B=1024B) 003FFH 07C00H(31K Start) Boot Sector Entry 00400H(1K Start) 07BFFH PC BIOS Memory Layout A0000H(640K Start) 9FFFFH B0000H(704K Start) EGA/VGA/XGA/XVGA Graphic Video Buffer B8000H(736K Start) Mono text video buffer C0000H(768K Start) CGA/EGA+ Chroma text video buffer FFFFFH FFFF0H BIOS Entry FE000H(1016K Start) BIOS Boot Block BIOS Routine & Card BIOS 80000H(512K Start) Boot Sector(512B) 07E00H Upper Memory Block Base Memory 386 Real Mode Address Low High 00500H BIOS Data Area Extended BIOS Data Area(usually 1K) 9FC00H High Memory Area(A20 on) 10FFFFH
Transcript of PC BIOS Memory Layout
00000HInterrupt Vector(256*4B=1024B) 003FFH
07C00H(31K Start) Boot Sector Entry
00400H(1K Start)
07BFFH
PC BIOS Memory Layout
A0000H(640K Start)9FFFFH
B0000H(704K Start)
EGA/VGA/XGA/XVGA Graphic Video Buffer
B8000H(736K Start)Mono text video buffer
C0000H(768K Start)CGA/EGA+ Chroma text video buffer
FFFFFHFFFF0H BIOS Entry
FE000H(1016K Start)BIOS Boot Block
BIOS Routine & Card BIOS
80000H(512K Start)
Boot Sector(512B)07E00H
Upp
er M
emor
y B
lock
Bas
e M
emor
y
386
Rea
l Mod
e A
ddre
ss
Low
High
00500HBIOS Data Area
Extended BIOS Data Area(usually 1K)9FC00H
High Memory Area(A20 on)10FFFFH
