I/O Map And Register Accessing; System I/O Map; Table 4-17. System I/O Map - Compaq Deskpro 4000N Technical Reference Manual

4.6

I/O MAP AND REGISTER ACCESSING

This section describes the system I/O map and methods of accessing various system functions.
4.6.1

SYSTEM I/O MAP

Table 4–17. System I/O Map
I/O Port
0000..000Fh
0020..0021h
0040..0043h
0060h
0061h
0064h
0070h
0071h
0078h..007Bh
007Ch..007Fh
0080..008Fh
0092h
00A0..00A1h
00B2h, 00B3h
00C0..00DFh
00F0h
015C, 015Dh
0170..0177h
01F0..01FFh
0201..024Fh
0278..027Bh
02F8..02FFh
0371.. 0375h
0376h
0377h
0378..037Fh
0388..038Bh
03B0..03DFh
03E8..03EFh
03F0..03F5h
03F6, 03F7h
03F8..03FFh
04D0, 04D1h
0C06, 0C07h
0C50, 0C51h
0C70..0C77h
0C82h
0CF8h
0CFCh
F800..F83Fh
NOTE: Assume unmarked gaps are reserved/unused.
Table 4-17.
System I/O Map
Function
DMA Controller 1
Interrupt Controller 1
Timer 1
Keyboard Controller Data Byte
NMI, Speaker Control
Keyboard Controller Command/Status Byte
NMI Enable, RTC Address
RTC Data
General Purpose I/O Port 1
General Purpose I/O Port 2
DMA Page Registers
Port A, Fast A20/Reset
Interrupt Controller 2
APM Control/Status Ports
DMA Controller 2
Math Coprocessor Busy Clear
87307 I/O Controller Configuration Registers (Index, Data)
Hard Drive (IDE) Controller 2
Hard Drive (IDE) Controller 1
Reserved.
Parallel Port (LPT2)
Serial Port (COM2)
Diskette Drive Controller Alternate Addresses
IDE Controller Alternate Address
IDE Controller Alternate Address, Diskette Drive Controller Alternate Address
Parallel Port (LPT1)
FM synthesizer (alias addresses)
Graphics Controller
Serial Port (COM3)
Diskette Drive Controller Primary Addresses
Diskette Drive Controller Primary Addresses, Hard Drive Controller Primary Addresses
Serial Port (COM1)
Master, Slave Edge/Level INTR Control Register
Reserved - Compaq proprietary use only
System Management Configuration Registers (Index, Data)
ACPI
Auto Rev Data (not used)
PCI Configuration Address (dword access)
PCI Configuration Data (byte, word, or dword access)
ACPI & GPIOs
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September1997
Technical Reference Guide
4-41