Wow, I essentially did this same project a number of years ago, but never finished it. My ship ran aground debugging division since it becomes long and convolut

Wow, I essentially did this same project a number of years ago, but never finished it. My ship ran aground debugging division since it becomes long and convoluted to do it, especially when also dealing with negative numbers and decimals. I also added an LED board that was an array of LEDs, one LED per relay, attached to it's coil. This way you could see the states of the calculator flash by as it computed, akin to those old blinking button boards of retro sci-fi. Really neat project!