hi, i have designed a circuit on chrocodile technology and everything works apart from when i press one of the 'set' switches, the MOSFET blows up and it says something about the drain voltage
6v should be fine, so i'm assuming its the lack of a protection diode on the relay coil? When the relay turns off, the inductance of the coil creates a brief high voltage spike which can damage both transistors and MOSFET's. Look here to see an example of how to use the protection diode:
Its rather an unusual symbol for a MOSFET too? Not the one i'm familiar with.