Output register

The output register is similar to any other register (like the A and B registers) except rather than displaying its contents in binary on 8 LEDs, it displays its contents in decimal on a 7-segment display. Doing that requires some complex logic; luckily there's an easier way:

Videos

Schematic

Data sheets

• 555 timer
• 74LS08 Quad AND gate
• 74LS107 Dual J/K flip-flop (substitute for 74LS76; check pinout!)
• 74LS139 Dual 2-to-4 line decoder/demultiplexer
• 74LS273 8-bit D register
• 28C16 16K EEPROM

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