36
Address Range
Size
Description
00000-7FFFF
512K
Conventional memory
80000-9FBFF
127K
Extended Conventional memory
9FC00-9FFFF
1K
Extended BIOS data area if PS/2 mouse is installed
A0000-C7FFF
160K
Available for Hi DOS memory
C8000-DFFFF
96K
Available for Hi DOS memory and adapter ROMs
E0000-EEFFF
60K
Available for UMB
EF000-EFFFF
4K
Video service routine for Monochrome & CGA adapter
F0000-F7FFF
32K
BIOS CMOS setup utility
F8000-FCFFF
20K
BIOS runtime service routine (2)
FD000-FDFFF
4K
Plug and Play ESCD data area
FE000-FFFFF
8K
BIOS runtime service routine (1)
I/O MAP
000-01F
DMA controller (Master)
020-021
INTERRUPT CONTROLLER (Master)
022-023
CHIPSET control registers. I/O ports
040-05F
TIMER control registers
060-06F
KEYBOARD interface controller (8042)
070-07F
RTC ports & CMOS I/O ports
080-09F
DMA register
0A0-0BF
INTERRUPT controller (Slave)
0C0-0DF
DMA controller (Slave)
0F0-0FF
MATH COPROCESSOR
1F0-1F8
HARD DISK controller
278-27F
PARALLEL port 2
2B0-2DF
GRAPHICS adapter controller
2F8-2FF
SERIAL port 2
360-36F
NETWORK ports
378-37F
PARALLEL port 1
3B0-3BF
MONOCHROME & PARALLEL port adapter
3C0-3CF
EGA adapter
3D0-CDF
CGA adapter
3F0-3F7
FLOPPY DISK controller
3F8-3FF
SERIAL port-1
3-14 TIME & DMA CHANNELS MAP
TIME MAP:
TIMER Channel 0 System timer interrupt