HP dc7900 manual System I/O Map, Port Function

System Support

		Table 4-9
		System I/O Map
	I/O Port	Function
	0000..001Fh	DMA Controller 1
0020..002Dh		Interrupt Controller 1
002E, 002Fh		Index, Data Ports to SIO Controller (primary)
0030..003Dh		Interrupt Controller
0040..0042h		Timer 1
004E, 004Fh		Index, Data Ports to SIO Controller (secondary)
0050..0052h		Timer / Counter
0060..0067h		Microcontroller, NMI Controller (alternating addresses)
0070..0077h		RTC Controller
0080..0091h		DMA Controller
0092h		Port A, Fast A20/Reset Generator
0093..009Fh		DMA Controller
00A0..00B1h		Interrupt Controller 2
00B2h, 00B3h		APM Control/Status Ports
00B4..00BDh		Interrupt Controller
00C0..00DFh		DMA Controller 2
00F0h		Coprocessor error register
0170..0177h		IDE Controller 2 (active only if standard I/O space is enabled for secondary controller)
01F0..01F7h		IDE Controller 1 (active only if standard I/O space is enabled for primary controller)
0278..027Fh		Parallel Port (LPT2)
02E8..02EFh		Serial Port (COM4)
02F8..02FFh		Serial Port (COM2)
0370..0377h		Diskette Drive Controller Secondary Address
0376h		IDE Controller 2 (active only if standard I/O space is enabled for primary drive)
0378..037Fh		Parallel Port (LPT1)
03B0..03DFh		Graphics Controller
03BC..03BEh		Parallel Port (LPT3)
03E8..03EFh		Serial Port (COM3)
03F0..03F5h		Diskette Drive Controller Primary Addresses
03F6h		IDE Controller 1 (active only if standard I/O space is enabled for sec. drive)
03F8..03FFh		Serial Port (COM1)
04D0, 04D1h		Interrupt Controller
0678..067Fh		Parallel Port (LPT2)
0778..077Fh		Parallel Port (LPT1)
07BC..07BEh		Parallel Port (LPT3)
0CF8h		PCI Configuration Address (dword access only )
0CF9h		Reset Control Register
0CFCh		PCI Configuration Data (byte, word, or dword access)

NOTE:

Assume unmarked gaps are unused, reserved, or used by functions that employ variable I/O address mapping. Some ranges may include reserved addresses.

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