Info from DUDEK Emil: Very high-quality feel to this compact and pretty calculator. Subtle grey, metal and blue coloring works very well. Original soft black plastic cover is open toped and embossed with Panasonic Electronic Calculator. The logic is OK with good recover but let down by negative square roots and a very basic memory function. The keyboard board is fixed to the front by a dozen plastic rivets. It connects to the main board, which sits loosely on top, via a 15-way ribbon cable Construction: Remove the single screw from the back and gently lift off the rear section. Logic comments: [CE] is used to clear last entry of a number and [C] clear the whole calculator. Overflow on number input is suppressed inputting a ninth digit is ignored. An overflow shows the result with a ‘C’ (or ‘E’ if negative) in the far left (ninth) digit and is recoverable using [CE] Divide by zero results in zero and a ‘C’ in the far left (ninth) digit and is recoverable using [CE]. There is automatic constant on all four functions. Negative square roots are allowed and give a negative result. Negative numbers are shown by a ‘-‘ in the far left (ninth) digit thereby allowing full eight digit negative numbers. Memory store is indicated by an upper “n” in the far left (ninth) digit. The action of the memory is automatic, the result of an equals key is automatically added to the memory. A press of [M] will recall the memory and clear it.