tincanman8:
EDIT: About the code I added to the top of the setup: yes, it did shorten the blink to about 7.8 seconds. What does that mean, though?
Well, it means several things...
• The processor appears to be functioning correctly.
• The initial speed is outside of the guaranteed ±10%. (Where did you buy the processor?)
• At this point, the only identifiable problem is the clock speed.
• You can very likely get your project working with some tuning.
Can you use that to modify the clock speed?
Absolutely. Adjusting OSCCAL is how the internal oscillator is tuned.
You can fiddle with OSCCAL until the timing is close. Increase the value to speed the processor. Decrease the value to slow the processor. When adjusting the value, use a while-loop like in Reply #20.
Or, you can use Poor Man's Tiny Tuner. Version 1 uses 'x' at 9600 baud for tuning. It gives good results but it was not meant to work with the t13 processor. You can find it with this...
https://www.google.com/search?q=poor+man's+tiny+tuner
Version 2 uses a timing signal from the programmer (your 2560 board). It gives better results and was meant to work with the t13 processor. It looks like I did not make a separate thread for it...
https://www.google.com/search?q=tiny+tuner+2+site:forum.arduino.cc
Erni graciously provides some documentation here...
http://ernstc.dk/arduino/tinytuner.html
I'm off to bed...