Grumpy_Mike:
Yes that is what he said, but was that what he meant?
To me it makes little sense asking exactly what he asked.
Why do you say that? If he using an external +12vdc power source plugged into the arduino external power plug and wants to then power some external devices that requires +12vdc, say a solenoid or relay using the +12vdc avalible at the Vin pin, then it's a very logical question to ask how much current can one safely draw from the Vin pin. The limit is the current rating of the external power source or one amp, whichever is less (minus whatever current the on-board regulator is drawing). No ?
Lefty