How to use UC-SGT on Mac OS X Mountain Lion 10.8.2 (15' rMBP 2012)

It's been ages since a serial port disappeared from a laptop PC. Nevertheless, network devices requires a serial connection as a our-of-band connection. I grabbed a USB serial adapter UC-SGT, but my laptop (15' rMBP 2012, Mountain Lion) needed a trick to recognize it.

1. Download a driver from a prolific's website
   http://prolificusa.com/pl-2303hx-drivers/
2. Install the driver following README
3. Add an entry for UC-SGT to the driver
   cd /System/Library/Extensions/ProlificUsbSerial.kext/Contents
   sudo cp -p Info.plist Info.plist.ori
   sudo vim Info.plist Info.plist.ori
   
   * Insert the following entry before the entry for <key>067B_2303</key>
            <key>056E_5004</key>
            <dict>
                <key>CFBundleIdentifier</key>
                <string>com.prolific.driver.PL2303</string>
                <key>IOClass</key>
                <string>com_prolific_driver_PL2303</string>
                <key>IOProviderClass</key>
                <string>IOUSBInterface</string>
                <key>bConfigurationValue</key>
                <integer>1</integer>
                <key>bInterfaceNumber</key>
                <integer>0</integer>
                <key>idProduct</key>
                <integer>20484</integer>
                <key>idVendor</key>
                <integer>1390</integer>
            </dict>


4. Rebuild kext cache
   sudo touch /System/Library/Extentions/
   sudo reboot

Caution: kext cache needs to be rebuilt; otherwise, you need to issue kextload /System/Library//Extensions/ProlificUsbSerial.kext  command every time you boot the box.

Note: TU-S9 from TRENDnet works on prolific's driver without changing plist.