IBM PC 300GL I/O address map, Address hex, Size, Description, Appendix B. System address maps

Table 33. I/O address map

Address (hex)	Size	Description
0280–02E7	102 bytes	Available
02E8–02EF	8 bytes	Serial port 3 or 4
02F8–02FF	8 bytes	COM2
0338–033F	8 bytes	Serial port 3 or 4
0340–036F	48 bytes	Available
0370–0371	2 bytes	SIO planar Plug and Play index/data registers
0372–0375	4 bytes	Available
0376–0377	2 bytes	IDE channel 1 command
0378–037F	8 bytes	LPT2
0380–03B3	52 bytes	Available
03B4–03B7	4 bytes	Video
03BA	1 byte	Video
03BC–03BE	16 bytes	LPT1
03C0–03CF	16 bytes	Video
0334–03D7	4 bytes	Video
03DA	1 byte	Video
03D0–03DF	11 bytes	Available
03E0–03E7	8 bytes	Available
03E8–03EF	8 bytes	COM3 or COM4
03F0–03F5	6 bytes	Diskette channel 1
03F6	1 byte	Primary IDE channel command port
03F7 (Write)	1 byte	Diskette channel command
03F7, bit 7	1 bit	Diskette disk change channel
03F7, bits 6:0	7 bits	Primary IDE channel status port
03F8–03FF	8 bytes	COM1
0400–047F	128 bytes	Available
0480–048F	16 bytes	DMA channel high page registers
0490–0CF7	1912 bytes	Available
0CF8–0CFB	4 bytes	PCI configuration address register
0CFC–0CFF	4 bytes	PCI configuration date register
OPTn–400h	8 bytes	ECP port, LPTn base address + hex 400
0CF9	1 byte	Turbo and reset control register
0D00–FFFF	62207 bytes	Available

Appendix B. System address maps 49