--On Wednesday, August 24, 2011 3:04 AM +0100 Always Learning centos@u61.u22.net wrote:
You need to do a little on-line reading about USB (the effective replacement for Centronics (parallel) ports and RS232/RS423 serial ports. Also about the PCI replacement called PCI-Express.
I see USB as being on par more with PCI-E than RS232/Centronics. It's a general external expansion bus, but lacks bus-mastering. Compare to Firewire, which adds bus-mastering. So for bus-level interfaces, use PCI-E inside the box, and USB or Firewire outside the box.
Ethernet and SATA interfaces then stack on top of PCI-E/USB/Firewire. (As does the older IDE now often referred to as PATA.)
The lspci and lsusb command line utilities can be used to view the topology of the buses. (Is there a Linux GUI tool similar to Windows Device Manager in view-by-connection mode to graphically show the topology? I've found that view a good way to get one's head around how this stuff goes together.)