Chapter 3 Hardware Description
10 AI5VG Pentium VP3 Baby AT Motherboard User’s Manual
3.8 I/O Port Address Map
Each peripheral device in the system is assigned a set of I/O port
addresses which also becomes the identity of the device. There are a total
of 1K port address space available. The following table lists the I/O port
addresses used on the motherboard.
Address Device Description
000h - 01Fh DMA Controller #1
020h - 03Fh Interrupt Controller #1
040h - 05Fh Timer
060h - 06Fh Keyboard Controller
070h - 07Fh Real Time Clock, NMI
080h - 09Fh DMA Page Register
0A0h - 0BFh Interrupt Controller #2
0C0h - 0DFh DMA Controller #2
0F0h Clear Math Coprocessor Busy Signal
0F1h Reset Math Coprocessor
1F0h - 1F7h IDE Interface
278 - 27F Parallel Port #2 (LPT2)
2F8h - 2FFh Serial Port #2 (COM2)
2B0 - 2DF Graphics adapter Controller
378h - 3FFh Parallel Port #1(LPT1)
360 - 36F Network Ports
3B0 - 3BF Monochrome & Printer adapter
3C0 - 3CF EGA adapter
3D0 - 3DF CGA adapter
3F0h - 3F7h Floppy Disk Controller
3F8h - 3FFh Serial Port #1 (COM1)
3.9 DMA Channels
There are seven DMA Channels available on the motherboard. Only
DMA2 is used by the floppy controller. In the case that ECP mode on the
parallel port is used, DMA1 or DMA3 will be used.