B.1   System I/O ports
    Table B-1: System I/O ports
    Addr. range
    (Hex)         Device
    000-01F       DMA controller
    020-021       Interrupt controller 1, master
    022-023       Chipset address
    040-05F       8254 timer
    060-06F       8042 (keyboard controller)
    070-07F       Real-time clock, non-maskable interrupt (NMI) mask
    080-09F       DMA page register,
    0A0-0BF       Interrupt controller 2
    0C0-0DF       DMA controller
    0F0           Clear math co-processor
    0F1           Reset math co-processor
    0F8-0FF       Math co-processor
    170- 178      2nd fixed disk for CompactFlash
    1F0-1F8       1st fixed disk
    200-207       Game I/O
    278-27F       Reserved
    2F8-2FF       Serial port 2
    378-37F       Parallel printer port 1 (LPT2)
    380-38F       SDLC, bisynchronous 2
    3A0-3AF       Bisynchronous 1
    3B0-3BF       Monochrome display and printer adapter (LPT1)
    3C0-3CF       Reserved
    3D0-3DF       Color/graphics monitor adapter
    3F0-3F7       Diskette controller
    3F8-3FF       Serial port 1
    443           Watchdog timer

B.2   DMA channel assignments
    Table B-2: DMA channel assignments
    Channel     Function
    0           Available
    1           Audio*
    2           Floppy disk (8-bit transfer)
    3           Parallel**
    4           Cascade for DMA controller 1
    5           Audio*
    6           Available
    7           Available

B.3    Interrupt assignments
    Table B-3: Interrupt assignments
    Interrupt#    Interrupt source
    NMI           Parity error detected
    IRQ 0         Interval timer
    IRQ 1         Keyboard
    IRQ 2         Interrupt from controller 2 (cascade)
    IRQ 8         Real-time clock
    IRQ 9         Reserve
    IRQ 10        Available
    IRQ 11        Reserved for watchdog timer
    IRQ 12        PS/2 mouse
    IRQ 13        INT from co-processor
    IRQ 14        Preliminary IDE
    IRQ 15        Secondary IDE for CompactFlash
    IRQ 3         Serial communication port 2
    IRQ 4         Serial communication port 1
    IRQ 5         Audio*
    IRQ 6         Diskette controller (FDC)
    IRQ 7         Parallel port 1 (print port)

B.4   1st MB memory map
    Table B-4: 1st MB memory map
    Addr. range (Hex)          Device
    F000h - FFFFh              System ROM
    D800h - EFFFh              Unused
    D000h - D400H              Available
    C800h - D7FFh              Ethernet ROM*
    C000h - C7FFh              VGA BIOS
    B800h - BFFFh              CGA/EGA/VGA text
    B000h - B7FFh              Reserved for graphic mode usage
    A000h - AFFFh              EGA/VGA graphics
    0000h - 9FFFh              Base memory

