I/O address (hex) System function (shipping configuration)
220 - 22F Entertainment audio
230 - 26D Unused
26E - 26 Unused
278 - 27F Unused
280 - 2AB Unused
2A0 - 2A7 Unused
2A8 - 2E7 Unused
2E8 - 2EF Reserved serial port
2F0 - 2F7 Unused
2F8 - 2FF Infrared port
300 - 31F Unused
320 - 36F Unused
370 - 377 Secondary diskette drive controller
378 - 37F Parallel port (LPT1/default)
380 - 387 Unused
388 - 38B FM synthesizer—OPL3
38C - 3AF Unused
3B0 - 3BB VGA
3BC - 3BF Reserved (parallel port/no EPP support)
3C0 - 3DF VGA
3E0 - 3E1 PC Card controller in CPU
3E2 - 3E3 Unused
3E8 - 3EF Internal modem
3F0 - 3F7 “A” diskette controller
3F8 - 3FF Serial port (COM1/default)
CF8 - CFB PCI configuration index register (PCIDIVO-1)
CFC - CFF PCI configuration data register (PCIDIVO-1)
System I/O address specifications—Intel processors 131