Rockwell 30R "Slide Rule Memory".

9v (PP3).

Display is 8 digits, red LED.

4 function, %, memory, square, square root.

The main chip is a Rockwell A4612PA here date coded late 1974.

76 x 153 x 23 mm (3.0" x 6.0" x 0.9").

Made in Great Britain, at the former Sumlock-Anita factory in Portsmouth.  See the page 'The Rockwell Connection'.