Есть исходник на Pascal
Вот пример информации об устройстве получившим один адрес в области ввода вывола в моем компьютере:

Bus 0 (PCI Express), Device Number 31, Device Function 3
Vendor 8086h Intel Corporation
Device 27DAh 82801G (ICH7 Family) SMBus Controller
Command 0001h (I/O Access)
Status 0280h (Supports Back-To-Back Trans., Medium Timing)
Revision 01h, Header Type 00h, Bus Latency Timer 00h
Self test 00h (Self test not supported)
PCI Class Serial, type SMBus Controller
Subsystem ID 81791043h Unknown
Subsystem Vendor 1043h ASUSTeK Computer Inc
Address 4 is an I/O Port : 00000400h
System IRQ 11, INT# B