Hardware Configuration and Specification Memory Address Map Address Range
Definition
Function
000000-09FFFF
640 KB memory
Base memory
0A0000-0BFFFF
128 KB video RAM
Reserved
0C0000-0CBFFF
Video BIOS
Video BIOS
0F0000-0FFFFF
64 KB system BIOS
System BIOS
100000-top limited
Extended memory
SIMM memory
FE0000-FFFFFF
256 KB system ROM
Duplicate of code assignment at 0E00000FFFFF
Interrupt channel default assignment Channel
Default setting
mode
Remarks
NMI
System errors
IRQ0
System timer
IRQ1
Keyboard
Edge
IRQ2
(cascade)
Edge
IRQ3
Infrared (COM2)
Edge
Dynamically programmable
IRQ4
Modem/COM1 (can be disable)
Edge
Dynamically programmable
IRQ5
Yamaha sound system audio
level
PnP/ISA
Edge
IRQ6
Floppy
Edge
IRQ7
Printer
Edge
IRQ8
Real time clock
Edge
IRQ9
PCI device
level
PCI interrupt sharing
IRQ10
Modem
Edge
Dynamically programmable
IRQ11
PCI device
level
PCI interrupt sharing
IRQ12
pointing device
Edge
IRQ13
Math coprocessor
Edge
IRQ14
Hard disk driver
IRQ15
CD-ROM driver
Chapter 1
Dynamically programmable
3
