Digital signal processors can represent irrational numbers using fixed-point or floating-point data types.
Fixed point means fixed number of decimal places, and floating point means floating number of decimal places.
There are advantages to each and it isn't always best to use a floating-point processor.
Still, where numerical precision matters, floating-point has a leg up, and I've been assuming a launch vehicle like the space shuttle or Saturn V would have used exactly that in its GNC systems.
But have I been assuming right? Or might it have been fixed-point instead?
Not a computer scientist. I know just enough about data types to get me in trouble. Please hold down your bazookas, kind people :D
Just found the text below suggesting the space shuttle in fact used fixed-point arithmetic. Now wondering if modern rockets use fixed-point too... and can someone confirm that the excerpt below really means 480,000 instructions per second for fixed-point against 7,000 for floating-point? That difference is huuuge and unexpected to me. Big thanks if you can confirm!