In engineering circles, this circuit is better known as a 7447 BCD to seven-segment decoder/driver, but just using a single chip has little pedagogical value.

Logic 0 will turn on a segment, and logic 1 will turn it off. A lookup table in the MCU code is used to generate the desired display. U4 can be two sections of a 74HC14 or one 74LVC2G14/NC7WZ14.

[Fran] demonstrates the display running with a CD4511B BCD-to-7-segment decoder, hooked up with a bunch of 3904 power transistors to get the chip working with filament bulbs instead of LEDs.