This was one of the first hand-held calculators, being launched in Japan in spring 1970...
The MAPS (Microprogrammable Arithmetic Processor System) or National MM570X was a system made of 5 discrete chips designed by National Semiconductor that can be programmed to operate in binary or BCD up to a 76 bit one cycle data word. The chipset was marketed as a general purpose serial data microcomputer system and was introduced in late 1971.