1-14 Service Guide

1.4 Hardware Configuration and Specification

1.4.1 Memory Address Map

Table 1-7 Memory Address Map

Address Range Definition Function

000000 - 09FFFF 640 KB memory Base memory
0A0000 - 0BFFFF 128 KB video RAM Reserved for graphics display buffer
0C0000 - 0CBFFF Video BIOS Video BIOS
0E0000 - 0EFFFF
0F0000 - 0FFFFF
128 KB system BIOS System BIOS
System BIOS
10000 - 7FFFF
80000 - 27FFF Extended memory Onboard Memory
SIMM memory
FE0000 - FFFFFF 256 KB system ROM Duplicate of code assignment at 0E0000-0FFFFF

1.4.2 Interrupt Channel Map

Table 1-8 Interrupt Channel Map

Priority Interrupt Number Interrupt Source

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
SMI
NMI
IRQ 0
IRQ 1
IRQ 2
IRQ 8
IRQ 9
IRQ 10
IRQ 11
IRQ 12
IRQ 13
IRQ 14
IRQ 15
IRQ 3
IRQ 4
IRQ 5
IRQ 6
IRQ 7
Power management unit
Parity error detected, I/O channel error
Interval timer, counter 0 output
Keyboard
Interrupt from controller 2 (cascade)
Real-time clock
Cascaded to INT 0AH (IRQ 2)
Audio (option) / PCMCIA
Audio (option) / PCMCIA
PS/2 mouse
INT from coprocessor
Hard disk controller
CD-ROM controller
Serial communication port 2
Serial communication port 1
Parallel port (option) / Audio
Diskette controller
Parallel port (option)

A PCMCIA card can use IRQ 3, 4, 5, 7, 9 and 11 as long as it does not conflict with the

interrupt address of any other device.

1.4.3 DMA Channel Map

Table 1-9 DMA Channel Map

Controller Channel Address Function

1 0 0087 Audio (option)/ECP(option)