PCI devices
<h2>Vendors</h2>
<p>
The top level of the hierarchy is the list of vendors.
Each vendor has a 2-byte ID, stored in the database as 4 hexadecimal digits (with lowercase letters).
They can be browsed <a href='/read/PC'>here</a>.

<h2>Devices</h2>
<p>
Each vendor keeps a list of his devices and assigns ID's to them.
Each device in the list has a 2-byte long ID, stored the same way as the vendor ID (4 hexadecimal digits).

<h2>Subsystems</h2>
<p>
Sometimes, a device ID is not sufficient to select the right driver. For example, the same
chip can be wired in different ways on different boards. In such cases, the manufacturer of
the board defines a subsystem ID for the board, which serves as an additional identification.
<p>
The subsystem ID's are 4 bytes long, stored as 8 hexadecimal letters with a space in the middle
(e.g., <tt>1234 abcd</tt> could be a subsystem ID).
The first quad of digits is the vendor ID (from the same list of vendors as the devices;
possibly different from the vendor of the device itself), the rest is assigned by the vendor.

<h2>See also</h2>
<p>
You can have a look at <a href='$HELP_URL$pci_class'>PCI device classes</a>.