In the mid to late 60s, electronic calculators were at the forefront of integrated circuit development, but it would take some time before the number of ICs could be reduced to manufacture small, lightweight calculators. It was also during this time that nixie tubes were commonly used to display the numbers on display devices, such as calculators. What are nixie tubes? They are vacuum tubes containing a wire-mess anode and multiple cathodes representing numbers 0-9. These numbers fill up with vibrant orange-colored gas when triggered. Fast-forward to the 21st century and hobbyists are now using these tubes to create clocks and watches just to watch those numbers light up in that awesome, retro glow.

Calculator: Friden EC-1113
Year Released: 1969

In 1965, Singer corporation bought out Friden resulting in the Friden brand being phased out. This calculator was one of Friden’s last products to keep their original name on the machine. The EC1113 has 12 nixie tubes and a groovy looking red power button that just screams “I’m retro and awesome, so please press me.”

Calculator: Monroe 990
Year Released: 1970

The Monroe 990 is a 16-digit nixie display calculator. It uses 8 integrated circuit boards and has some serious presence. It is identical to the Canon 163 except that the black and white colors are reversed on the case. (Did they really think that would fool us?). Since Canon designed and built the 990 for Monroe, I guess I can’t be too surprised they’d use their own design for their own product.

Here’s a review of the machine and look at its innards: