I've been trying to figure out if it is possible to program an Arduino Ethernet board (http://www.arduino.cc/en/Main/ArduinoBoardEthernet) via RS232. I found this post online: http://blog.solutions-cubed.com/programming-the-arduino-uno-with-a-serial-port/
that describes how to program an Arduino Uno via RS232. Apparently, there is a separate micro controller on the Uno dedicated to programming via USB. The solution in the link above removes a few components from the Arduino Uno to bypass the USB programming interface.
Since the Arduino Ethernet board does not have this interface, would it be possible to simply use an RS232 converter IC like the MAX202 between a serial connector and the TX, RX pins of the Arduino? I'm not too sure how connecting a capacitor between the DTR logic level output of the RS232 IC and the Reset pin on the Arduino resets the Arduino at the right moment. Do I also need a resistor in series with the cap?