APOLLO GUIDANCE COMPUTER SOFTWARE
APOLLO GUIDANCE COMPUTER CODE

APOLLO GUIDANCE COMPUTER SOFTWARE

The AGC also included a software intrepreter to handle complex calculations and data processing. When the dummy job ran, it meant the AGC software had nothing better to do and the green computer activity status light was turned off. The Exec always had one lowest priority job to run, called the dummy job, to check the system status. The Waitlist held tasks waiting for the Exec to have capacity to run them.

Exec could run up to eight tasks at a time with each task periodically checking back with the Exec to see if a task with a higher priority was waiting to run. The operating system was called Exec and it managed jobs based on priority. The PROG status light lit when the DSKY needed additional information from the crew to complete the requested program, for example, to enter position data for the telescope used to navigate. For example, the No ATT warning light is lit when the inertial subsystem, which tracks the location of the spacecraft, could not provide an attitude reference. Warning and status lights are on the top left while the activity displays on the top right.

Here is a NASA illustration of the Apollo AGC, which differs a little from the AGC in the video above. WidnallвЂ™s lecture video linked below, women made critical contributions to many parts of the AGC program. Also note that, while men are everywhere in this video and Dr. This video also provides an overview of the guidance-related problems the AGC had to solve in real time as the astronauts flew to the moon and back. HereвЂ™s an old NASA video which shows how the DSKY worked, about 6 minutes into the program:

The backend computer processed the commands entered with buttons and returned data to the display screen. It had status lights, a display for data, and buttons to enter commands. The front end with buttons was called DSKY, shorthand for display and keyboard, and pronounced dis-key. While the command module and lunar lander each had an AGC, the software on them was different because each spacecraft had a different purpose. For example, the flight data for speed, altitude, and other metrics. The AGC had two parts, a front end device with buttons and a backend processing computer which processed data from the front end device as well as data from various devices within the Apollo command module and lunar lander.

APOLLO GUIDANCE COMPUTER CODE

The Apollo code can be studied online and run within a virtual Apollo Guicance Computer (AGC) emulator. For the 40th anniversary of the first moon landing, in 2009, Google made available online AGC code which Ron Burkey and others had transcribed into digital code from these printouts. As computers and digital storage have evolved (do you remember the 5 inch floppy disk?), for decades the Apollo code was locked in paper printouts. The Apollo moon landing missions used a lot of programming code to guide each mission. However, most people donвЂ™t think to save their code beyond, at most, saving the code to a repository. Programming has been around long enough, since the 1930s and 1940s, to have its own history. When we think of history, we might think of famous politicians or military leaders or athletes. Learn about and explore the code used to guide Apollo missions. Twitter Lists for Programming and Computer Science.

Apollo guidance computer