Technical Information 1-9
I/O Addressing
The processor communicates with I/O devices by I/O mapping. The hexadecimal (hex)
addresses of I/O devices are listed in Table 1-4.
Table 1-4 I/O Address Map
Address (Hex)
I/O Device Name
0000-000F
PIIX3 - DMA controller 1 (channel 0-3)
0020-0021
PIIX3 - Interrupt controller 1
002E-002F
87308B I/O base configuration registers
0040-0043
PIIX3 - Timer 1
0048-004B
PIIX3 - Timer 2
0060
Keyboard controller byte - Reset IRQ
0061
PIIX3 - NMI, speaker control
0064
Keyboard controller, command/status byte
0070, bit 7
PIIX3 - Enable NMI
0070, bits 6 through 0
PIIX3 - Real time clock, address
0071
PIIX3 - Real time clock, data
0078-0079
Reserved - board configuration
0080-008F
PIIX3 - DMA page registers
00A0-00A1
PIIX3 - Interrupt controller 2
00C0-00DE
PIIX3 - DMA controller 2
00F0
Reset numeric error (numeric data processor)
0170-0177
Secondary IDE channel
01F0-01F7
Primary IDE channel
0200-0207
Game port
0220-022F
Yamaha audio
0278-027F
Parallel port 2
02F8-02FF
Onboard serial port 2
0330-0331
MPU-401 (MIDI)
0376
Secondary IDE channel command port
0377
Secondary IDE channel status port
0378-037F
Parallel port 1
0388-038B
Yamaha audio
03BC-03BF
Parallel port 3
Summary of Contents for MT-2550-24874C
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