IBM Aptiva C66 (250-0458) System Resources Faxback Doc. # 34533 This table shows the hexadecimal addresses for each of the system board input/output (IO) functions. You may want to use this information if you install an adapter card that requires you to set I/O or addresses. Table 10: System I/O addresses Address range Function (hexadecimal) 0000-001F DMF controller 0020-0021 Interrupt controller 1 0040-0043 System timers 0060 Keyboard/mouse controller 0061 System control port B 0064 Keyboard/mouse controller 0070-0071 RTC/CMOS and NMI mask 0080-008F DMA controller 00A0-00A1 Interrupt controller 2 00B2-00B3 Reserved 00CO-00DF DMF controller 00EA-00ED Reserved 00F0-00FF Math coprocessor 0170-0177, 0376 Secondary IDE controller 01FO-01F7, 03F6 Primary IDE controller 0220-022F, 0388-0389 Mwave sound 0278-027F,67B-67A Parallel port 3 02E8-02EF Serial port 4 02F8-02FF Serial port 2 0330-0333 Mwave MIDI 0370-0371 Reserved 0378-037F, 77B-77A Parallel port 2 03BC-03BF, 7BC-7BE Parallel port 1 03CO-03CF, 3D4, 3D5, 03DA SVGA controller 03E8-03EF Serial port 3 03F2-03F5, 03F7 Diskette controller 03F8-03FF Mwave modem/fax or serial port 1 04DO-04D1 Reserved 0CF8-0CFC Reserved CE30 Mwave system FE80-FE8F Bus master IDE controller FF00-FFFF SVGA controller System interrupts This table shows the system interrupt request (IRQs) and their functions. You may use this information if you install an adapter card that requires you to set IRQs. Note: IRQ 11 may be used if Hardware MPEG is enabled. Table 11: System board interrupts Interrupt request (IRQ) Function SMI Power management NMI Parity error I/O channel check 0 Timer 1 Keyboard 2 Cascade to IRQ8-IRQ15 3 Serial port A 4 Mwave modem 5 Mwave sound 6 Diskette 7 Parallel port 8 Real-time clock 9 Mwave MIDI 10 Mwave DSP 11 User available 12 Mouse 13 Math coprocessor 14 Primary IDE 15 Secondary IDE DMA channel assignments This table shows the channel assignments for direct memory access (DMA). DMA allows I/O devices to transfer data directly to and from memory. You may need to select an open DMA channel if you add an I/O device that uses DMA. Table 12: DMA channel assignments DMA channel Assignment 0 User available 1 Mwave sound 2 Diskette 3 ECP parallel port (default) 4 Cascade 5 User available 6 User available 7 Mwave system Serial port addresses IBM Aptiva PCs have a built-in external serial port already installed in the computer. The connector for this port is located at the back of your computer. This port can be used to connect a serial mouse, serial printer, or other serial device and to transfer data between computers. The built-in serial port supports these addresses and interrupts. Address Windows 95 Interrupt Default 3F8 COM1 IRQ4 Modem 3E8 COM3 2F8 COM2 IRQ3 Serial port A 2E8 COM4 Conflicts may arise if you add adapter cards with serial ports or if you change the address settings on your modem if you are using an operating system other than Windows 95. You can resolve most of these conflicts by using the Setup Utility to change serial port addresses. See "Changing input/output port configuration" on page 37 for more information. (BR/BKL-09/05/96)