The Boots 224 Memory is a slim, handheld calculator from 1978. Made in Japan for the Boots brand, it was actually manufactured by Casio. This becomes obvious when looking at the design, which resembles Casio’s own Memory B-1 model.
The 224 Memory measures about 77mm wide, 136mm tall, and 20mm deep. It weighs around 110g without batteries. Power comes from two AA batteries, providing 3V DC. A socket on the top left side can also accept an AC adapter.
The case uses cream and brown plastics, with brushed aluminum accents. It has an on/off switch positioned for easy thumb access. The tilted display filter gives the blue vacuum fluorescent display a pleasing hue.
The display shows 8 digits, lacking a dedicated exponent digit. The 224 Memory performs basic four function arithmetic, percentages, delta percent, square roots, and offers 3-register memory. An overflow error shows “E” in the rightmost digit. Divide by zero also gives an error.
Inside, the main logic board connects to the keyboard board with 16 wires. The NEC D1877C microprocessor and NEC VFD tube provide the calculating power. Additional components include transistors, diodes, resistors, and capacitors.
While very similar to the Casio original, the 224 Memory loses the ninth digit. This limits negative numbers to 7 digits and precludes negative roots. However, the blue button coloring gives it a more attractive look. For basic portable calculating needs, the 224 Memory provides good functionality in a quality package.
There was another version of the Boots 224 Memory calculator as shown below. The variant version appears to be largely the same calculator internally, with the same display, logic board, and other components as the original version. The main difference is in the key coloring.