DEC Digital PC 3500 System Reference Manual page 167

Device Mapping
Range (hexadecimal)
2F8 - 2FF
378 - 37A
388 - 38B
3BC - 3BE
3E8 - 3EF
3F0 - 3F7
3F6 - 3F7
3F8 - 3FF
4D0
4D1
CF8 - CFF
B-4
Function
COM2
LPT1
Audio, FM music synthesizer
LPT3
COM3
Diskette (floppy disk) controller
Primary/secondary IDE controller (alt status, device address)
COM1
Edge/level control register - INTCNTRL1
Edge/level control register - INTCNTRL2
PCI configure space control register