I did a couple of searches, but I don't know what it's called exactly.
Is there a way to make the Arduino boot right into the sketch and not do it's startup routine? I've making a MIDI interface and whenever I have the MIDI hooked up to the equipment I'm controlling, it seems that whatever information the Arduino is sending on bootup is sending patch changing messages or something, which is a bit annoying.
I plan on housing it permanently and don't want to have to switch back to the patches I'm on every time the Arduino boots up.
That is probably the bootloader program interacting with any serial traffic it sees on the serial input pin when the chip is first powered up.
There is a way if you have a hardware programmer to erase the bootloader and only program in your sketch HEX file, thus making it a standalone chip that won't then be able to work with the Arduino IDE unless you reprogram the bootloader code back into the chip. The info is somewhere in the Arduino playground area.
I believe the "Lady Ada Bootloader" skips directly to the Sketch on power-up. I also believe that Sparkfun sells processors with her bootloader already installed. Buy a processor with the "Lady Ada Bootloader", download your Sketch, and you should be good to go.
(be sure to verify these two things before making a purchase)
It since it still boots up slowly when you press reset, but there after boots up right away. Does powering it up from being off "reset" the Arduino, or does it go right into running a sketch?
Would I just upload the Adaboot onto the Arduino using the ICSP header on the Arduino?
Is there a downside to using the Adaboot? Like would I only want to do this to the Arduino I plan on embedding, or is it an all around better bootloader? (Why isn't it standard if so)
Would I just upload the Adaboot onto the Arduino using the ICSP header on the Arduino?
Yes.
Is there a downside to using the Adaboot?
I have not read about any downsides. I've not used her bootloader so, once again, I cannot give you a straight answer.
Like would I only want to do this to the Arduino I plan on embedding, or is it an all around better bootloader?
It's my understanding that there are few or no issues with it so I suggest considering it a better choice. I also suggest modifying only a single Arduino until you've had time to decide for yourself if you prefer her bootloader. If you modify all the ones you have and run into problems, it may get a little frustrating having to put back the original bootloader!
If you're considering using a "better bootloader", you may want to have a look at Optiboot...