Spot-On Apollo Guidance Computer Simulator Contains Three Arduinos
If you've ever wondered what it was like to use an Apollo Guidance Computer, this Arduino-based simulator is a recreation of the DSKY.
The Apollo program was impressive for a number of reasons, including that Apollo spacecraft navigated using very rudimentary computers. The original Apollo guidance computer ran at a mere 2.048 MHz, had 2048 words of magnetic core RAM, and had 36,864 words of core rope memory for ROM. To put that into perspective, a modern smart light bulb is several times more powerful. Astronauts interacted with the Apollo Guidance Computers through a DSKY (Display and Keyboard) interface, which was similar to a terminal. If you've ever wondered what it was like to use an Apollo Guidance Computer, this Arduino-based simulator provides a faithful recreation of the DSKY.
The DSKY was the interface that astronauts used to run programs on the Apollo Guidance Computer. Like many computers from the era, it ran code comprised of a simple syntax of nouns and verbs. Those "words" were represented numerically, with verbs describing the action to take (like addition) and nouns specifying the data on which the action would take place. The DSKY's right screen displayed the current program number, the current verb, and the current noun in the top half. The bottom half displayed the resulting data. The left "screen" was an array of status and indicator lights. Below the screens, there was a numerical keyboard and a few function keys.
Operating the Apollo Guidance Computer through the DSKY was nothing like using a modern computer, which is why this simulator is so cool. It replicates the DSKY almost exactly and users can use it in conjunction with simulation software running on a modern computer. A custom PCB contains two 2.8" LCD screens, the 19 keyboard buttons, and three Arduino development boards. Two Arduino Nano boards control the LCD screens and an Arduino Mega monitors the keyboard. The Mega also connects to the host computer that runs the MoonJS simulation software. When powered on and connected, users can operate the DSKY simulator exactly like the real thing. They can enter verbs and nouns to run programs and the data and status lights will respond realistically.
If you want to get your hands on this DSKY simulator, it is currently for sale on Tindie for $250.