Technical Information 1-13
Table 1-4 I/O Address Map*
Address (Hex)
I/O Device Name
0376
Secondary IDE channel command port
0377
Floppy Channel 2 command
0377, bit 7
Floppy Disk Change, Channel 2
0377, bit 6 through 0
Secondary IDE channel status port
0378-037F
Parallel port 1
0388-038D
AdLIB (FM synthesizer)
03B4-03B5
Video (VGA)
03BA
Video (VGA)
03BC-03BF
Parallel port 3
03C0-03CA
Video (VGA)
03CC
Video (VGA)
03CE-03CF
Video (VGA)
03D4-03D5
Video (VGA)
03DA
Video (VGA)
03E8-03EF
COM3
03F0-03F5
Floppy channel 1
03F6
Primary IDE channel command port
03F7 (write)
Floppy channel 1 command
03F7, bit 7
Floppy disk change channel 1
03F7, bit 6 through 0
Primary IDE channel status port
03F8-03FF
COM1
04D0-04D1
Edge/level triggered
0530-0537
Windows sound system
0604-060B
Windows sound system
LPTn + 400h
ECP port, LPT n base a 400h
0CF8-0CFB**
PCI configuration address register
0CF9***
Turbo and reset control register
* In Plug and Play systems, these addresses are typical but may vary by configuration.
** Only accessible by DWORD accesses.
*** Byte access only.