National Semiconductor Novus 650 Mathbox Handheld Electronic Calculator

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This handheld electronic calculator has a black plastic case and fifteen rectangular plastic keys. These include ten digit keys, a clear entry/clear key, and four arithmetic function keys. The + key also serves as an enter key. Behind the keys is an on/off switch. Text next to it reads: Mathbox. Behind this is a red LED display. Advertisements indicate this showed up to six-digit results. A mark near the back of the calculator reads: NOVUS (/) 650. A jack for a power adapter is on the left side.
The back of the calculator has a compartment for a nine volt battery. The cover of the battery compartment in this example is tan, not matching the rest of the case.
A sticker on the back gives operating instructions. It reads at the top: NOVUS 650. It reads near the bottom: NOVUS – Consumer Products from (/) National Semiconductor Corporation (/) Made in U.S.A. The sticker also reads: Serial No. (/) 1366399.
The Novus Mathbox 650 is unusual among non-HP calculators in using reverse Polish notation. Prices found range from $15.00 in 1974 down to $4.88 in 1976.
[Advertisement], Chicago Tribune, December 8, 1974, p. E30. Advertises the Mathbox as on sale for $15.00.
[Advertisement], Washington Post , February 16, 1975, p. 18. Sale price for Novus 650 given as $14.88, a $5 savings.
[Advertisement], Washington Post, March 12, 1975, p. A9. Novus 650 advertised on sale for $12.99, originally $19.99.
[Advertisement], Washington Post, April 11, 1975, p. A24. Novus 650 on sale for $10.98.
[Advertisement], Washington Post, February 4, 1976, p. B15. Sale price for Novus 650 was $7.99.
[Advertisement], Washington Post, November 2, 1976, p. A15. Sale price for Novus 650 was $4.88, regularly $6.99.
Currently not on view
date made
National Semiconductor Corporation
place made
United States
Physical Description
plastic (case; keys; display cover material)
metal (circuitry material)
paper (sticker material)
overall: 1 in x 2 5/8 in x 5 in; 2.54 cm x 6.6675 cm x 12.7 cm
ID Number
catalog number
accession number
Credit Line
Gift of John B. Priser
See more items in
Medicine and Science: Computers
Handheld Electronic Calculators
Computers & Business Machines
Data Source
National Museum of American History


"A math nerd, even at the age of 8, I begged my parents to buy me a calculator. They said no, but also that they wouldn't prevent me from buying one with my own allowance. So in the fall of 1975, I bought myself a Novus Mathbox. Mine is in a cream-colored case, but otherwise identical to the one pictured here (and still worked last time I tried, but it's been a while since I've used a 9V battery for anything other than a smoke detector). The article mentions that the calculator uses RPN, which is correct. Another unusual trait (and one which marked this as a low-end calculator even for this time) is the lack of a decimal point. The calculator could do only integer arithmetic -- so, for example, computing 15 ÷ 7 would give the answer 2. The manual suggested to pad the dividend with zeroes to get a more precise quotient (e.g., computing 15000 ÷ 7 would give the result 2142 and therefore 15 ÷ 7 was approximately 2.142) -- at the time, I thought this "trick " was both arcane and magnificent."

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