IRQ and I/O Port Address C-3

I/O Port Address

The factory-set I/O port addresses for the server are assigned as follows:

Address Chip in Use
00 - 1F 8-bit DMA control register
20 - 21 Master 8259 programming interface
2E - 2F Configuration
40 - 43 8254 programming interface
60 Keyboard & mouse
61 NMI status register
64 Keyboard & mouse
70 - 71 NMI enable register/real-time clock
80 - 8F 16-bit DMA control register
A0 - A1 Slave 8259 programming interface
C0 - DF DMA controller page register
E0 - E9 Base address register
F0 Register IRQ13
F1 - FF Logical device configuration
170 - 177 or BAR2 EDMA2-compatible mode primary command block register
1F0 - 1F7 or BAR0 EDMA2-compatible mode secondary command block register
278 - 27F (Parallel port 3)
2F8 - 2FF Serial port B
BAR or 376 EDMA2-compatible mode secondary command block register
370 - 377 (Floppy disk drive 2), IDE 2
378 -37F (Parallel port 2)
3B0 - 3BB VGA
3BC - 3BE Parallel port 1
3C0 - 3DF VGA
3F6 or BAR1 EDMA2-compatible mode primary command block register
3F0 - 3F7 Floppy disk drive 1, IDE 1
3F8 - 3FF Serial port A
40B DMA1 expansion write mode register
4D0 Master 8259 ELCR programming
4D1 Slave 8259 ELCR programming
4D6 DMA2 expansion write mode register
580 - 58F SMBus control
900-93F PHPC1 register
940-97F PHPC2 register
C00 PCI IRQ mapping index register
C01 PCI IRQ mapping data register
C14 PCI error status register
C49 Address & status control
C4A Rise time counter control
C52 General register (GPMs)
C6C ISA wait register