Author Topic: Apollo AGC and my new favorite bug  (Read 1537 times)

0 Members and 1 Guest are viewing this topic.

Offline HP-ILnerd

  • Frequent Contributor
  • **
  • Posts: 260
  • Country: us
Apollo AGC and my new favorite bug
« on: March 18, 2016, 09:14:36 am »
Here's a 48 minute talk at Code Mesh London on the Apollo Guidance Computer.  The first part is just historical background, but they get into a lot of nice (and at the time innovative) technical fiddly bits on the operation and design of the AGC.
As for my favorite bug:  The AGC on the LM was programmed to interpret a certain signal from the landing radar that it had landed.  Apparently there are just 3 craters on the moon that are shaped in a way that radar reflecting off of them would fool the LM's AGC into thinking it had landed, and shut off the engine prematurely. 

There's a couple spots where the presenter misspeaks (I know:  astonishing that such a thing could happen during a live presentation), but generally a really nice talk if the subject appeals to you.

Offline German_EE

  • Super Contributor
  • ***
  • Posts: 2174
  • Country: de
Should you find yourself in a chronically leaking boat, energy devoted to changing vessels is likely to be more productive than energy devoted to patching leaks.

Warren Buffett

Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo