since it (they) are so important to the function of the sketches, and information on it (them) is rather vague.
How they are created!
What happens to them!
Where they are stored!
How they can be modified, if user finds it necessary!
What effect they have on the whole operation!
posted by: westfwBut they're NOT important. Important options show up in the menus of the IDE. preferences.txt holds the things that the IDE "remembers" between invocations (like which sketch you're working on), and it holds settings or a bunch of UN-important options that the IDE designers implemented but left out of the actual IDE because "too many options make a program confusing" (which is quite true.)
avrdude: stk500_get sync(): not in sync resp+0x00avrdude: stk500_disable():protocol error, expect=0x14, resp=0x51
Posted by: westfw A generally "correct" piece of advice is that if your brand new arduino doesn't upload programs, you should contact the vendor for advice or replacement. But that's so "general" as to not be very helpful.)
Posted by: westfwDid you try "tools/burn bootloader/parallel programmer" with your parallel programmer (I assume you built it yourself? Good job getting it working!)
Posted by: BroHoganI do know, for a fact, that if you make the cable too long on a parallel programmer it won't work, or will work intermittently.