MRBurnetet
You are right
However, I noticed that when I compile for the attiny85 or 45 all is well, finds the pins_arduino.h file in the user path... but the 2313 keeps looking in the core path... where there is no such file and then generates an error on compile, though it has its own pins_arduino.h in the user path
I am sure I made a small stupid error somewhere... but havent foun dit yet.
Ah found it.. I was putting it in the wrong attiny2313 folder ( IDE 1.0 structure) rather than in the proper attiny2313 folder (according to IDE 1.6.x structure).