Note that these techniques only work with the Arduino Duemilanove w/ an ATmega328, not the Arduino Uno (or older Arduino boards w/ an ATmega168).
You can buy a spare chip with the "standard" Arduino boot loader on it.
A) Do I need to get 2 Arduino boards to be able to do that? (I think not)
B) Do I need an external clock crystal? (B1)if so...Why? ) (B2)any disadvantage (i.e. different result) if I dont have that?)
C) The site linked says: QuoteNote that these techniques only work with the Arduino Duemilanove w/ an ATmega328, not the Arduino Uno (or older Arduino boards w/ an ATmega168).But (confusion?) continues with explaining about the Uno board? => is the uno(rev3) or is it not possible to be done with it?
Are you selling those?
kup Atmega328PU.4) I have only this:The Arduino UNO REV3PC-USB-connection to the arduinoa breadboarda 12V power suply I can plugin at the Arduino.5) I do not have:a second Arduinoa ISP-specially made devicea external clock crystalvery experienced background in electronics