+Home     Museum     Wanted     Advertising     Articles     EMail  

Denon DEC-521 Desktop Calculator

DEC-521 Image Courtesy Rick Furr (left)
Columbia COLCA 52 Image Courtesy Takaharu Yoshida (right)
Sincere thanks to both of these gentlemen for providing these images.

Denon was an OEM customer of Nippon Columbia Co., Ltd. in Japan. This calculator was made in Japan by Nippon Columbia, Co., Ltd. and sold in North-American markets as the Denon DEC-521. It was sold in Nippon Columbia's native markets as the Columbia COLCA 52. The calculator is made with a mix of small- and medium-scale MOS Integrated Circuits and discrete diode-transistor logic. The DEC-521 provides a capacity of twelve digits utilizing a uses twelve-digit Nixie tube display. The calculator provides the four basic math functions, with fixed decimal location, and an accumulating memory register and constant storage. It was introduced in Japan in May of 1970.

See the Old Calculator Web Museum exhibit on the Denon 61A4 for an earlier example of Denon's first desktop electronic calculator, also manufactured for Denon by Nippon Columbia, Co., Ltd.