14 System IntroductionsDMA Channel Assignment
DMA Channel Function
DRQ0 Audio(optional)
DRQ1 ECP or Audio(optional)
DRQ2 Floppy
DRQ3 ECP(optional)
DRQ4 DMA controller
DRQ5 Not used
DRQ6 Not used
DRQ7 Not used
I/O Address Map
I/O Address Function
000-00F DMA controller-1
020-021 Interrupt controller-1
040-043 Timer 1
060, 064 Keyboard controller 8742 chip select
061 System speaker out
040B DMA controller-1
061 System speaker
070-071 Real-time clock and NMI mask
080-08F DMA page register
0A0-0A1 In terrupt controller-2
0C0-0DF DMA controller- 2
0F0-0FF Numeric data processor
120-13F, 180-18F Power management controller
170-177 2nd EIDE device (CD-ROM) sele ct
1F0-1F7 1st EIDE device (hard drive) select
220-22F Audio
240-24F Audio(optional)
278-27F Parallel port 3
2E8-2EF LT Win modem or CO M4 (optional)
2F8-2FF COM2 or LT Win modem(optional)
378, 37A Parallel p ort 2
3BC-3BE paraller port 1