Chapter 1 15
IRQ15 CD-ROM driver
DMA channel default assignment
Channel Default setting Mode
DRQ/DACK0 Reserved 8-bit
DRQ/DACK1 ECP 8-bit
DRQ/DACK2 Floppy 8-bit
DRQ/DACK3 Fast Infrared 8-bit
DRQ/DACK5 Reserved 16-bit
DRQ/DACK6 Reserved 16-bit
DRQ/DACK7 Reserved 16-bit
I/O address map
Address Device
000-00F DMA controller-1
020-021 Interrupt controller-1
040-043 Timer 1
048-04B Timer 2
060-06E Keyboard controller 8742 chip select
070-071 Real-time clock and NMI mask
080-08F DMA page register
0A0-0A1 Interrupt controller-2
0C0-0DF DMA controller-2
1F0-1F7 Hard disk select
220-22F Audio (option)
230-23F Audio (option)
240-24F Audio (option)
250-25F Audio (option)
278-27F Parallel port 3
2E8-2EF COM4
2F8-2FF COM2
378, 37A Parallel port 2
3BC-3BE Paraller port 1
3B4, 3B5, 3BA Video subsystem
3C0-3C5 Video subsystem
Interrupt channel default assignment
Channel Default setting mode Remarks
720.book Page 15 Saturday, March 6, 1999 10:00 AM