Thank you for the very informative post - it has answered a couple of my questions..... and gave rise to a couple more.
The Diecimila schematic shows the two parts in the RTS and DTR line both as "100_NM" resistors, while the
http://arduino.cc/en/uploads/Main/arduino-duemilanove-schematic.pdf schematic shows the RTS as a "R2, 100_NM" resistor and "DTR as C13, 100nF".
Should I use two 100 ohm resistors? OR one 100 ohm resistor and one 100nF capacitor?
I am building a board to emulate the Arduino with a ZIF socket mounted that will allow programming from the Arduino IDE program. Most of my projects are mounting the programmed m168 chip on a separate PCB for a project (voltmeter, temperature controller, etc). While working up the program I am constantly moving m168 chip from project PCB to the Arduino for programming. Seems like it would be easier to move to a board with a ZIF socket to burn program - and save wear 'n tear on my Arduino board. So, I got a FT232RL chip, laying out a PCB for toner transfer in Eagle to a ZIF socket. I am duplicating the portion of the Arduino schematic to accomplish this.
Thank you again for your help -
Ken H>