Novus 750 Calculator Teardown

ID: 192267

Description: A late 1970s Calculator from National...

Steps:

1. My Novus 750 was made in 1976 by National Semiconductor under the “Novus” brand name. It features a 6 character bubble LED screen, and the ability to do basic four function calculations. It also takes a standard 9 volt battery as well.

2. To begin disassembly, open the battery cover on the backside of the calculator. Next, disconnect the 9V battery from the connector.

3. Once the battery is removed, use a Philips head screwdriver to unscrew the four screws holding the calculator together.

4. After all four screws are removed, the calculator can be opened by separating the two halves of the case.
5. Inside the calculator, there isn’t much. It has a small PCB with a chip-on-board microcontroller, and a small PCB for all of the number keys.

6. The PCB is very sparse of components due to component integration becoming more common. Under the black blob, there is a silicon microcontroller with all of the components integrated inside.
7. The bubble LED screen is quite interesting, since you can actually see the individual bond wires connecting to the LEDs. If you also connect power and turn the calculator on, you can see the LEDs up close.

8. “0.7734” on a calculator spells “HELLO” if you look at it upside down.