Manual Number: 00650-146-1
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PCI-COM485/8 Manual
Chapter 4: Address Selection
The PCI-COM485/8 card uses one address space. COM A, COM B, COM C, COM D, COM E,
COM F, COM G and COM H each occupy eight consecutive register locations. The interrupt
register which indicates which port or ports caused the interrupt is located at base a 64.
PCI architecture is inherently plug-and-play in nature. This means that the BIOS or Operating
System determines the resources assigned to PCI cards rather than you selecting those resources
with switches or jumpers. As a result, you cannot set or change the card’s base address. You can
only determine what the system has assigned. To determine the base address that has been as-
signed, run the provided PCIFind.EXE, or PCINT utility program.
Alternatively, some operating systems (Windows95 and WindowsNT 5.0) can be queried to deter-
mine which resources were assigned. In these operating systems, you can use either PCIFind (DOS),
PCINT (Windows95/98/NT), or the Device Manager utility from the System Applet of the control
panel. The PCI-COM485/8 is installed in the Data Acquisition class of the Device Manager list.
Selecting the card, clicking Properties, and then selecting the Resources Tab will display a list of
the resources allocated to the card.
The PCI bus supports 64K of I/O space, so your card’s addresses may be located anywhere in the
0000 to FFFF hex range.
