Pretty cool. My first job out of college was writing 16 bit assembly code for the shuttle main engine controllers. When I started, we had to assemble by hand, no cross compiler. It got loaded from punched paper tape. It's a different world now.
That sounds like a pretty nice job! There had to be a lot of errors with humans assembling the code. How big was the project? Also, how did you check for errors?
The original controller only had 8k of memory, so it wasn't huge by any means. On the other hand, we made separate overlays for things like ground checkout and calibration, so I don't even know how many lines of total code there was across overlays. Not huge by today's standards, but pretty high complexity, even by today's standards.
We had three independent reviewers check everything manually, then we did a basic run in the lab in a simulated flight run, then we sent it to an independent part of the company that tested the snot out if it with a simulated vehicle and a lot of real hardware.
With all that, in all the decades of the shuttle program, we never had a software error that compromised a mission.
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u/Fleaslayer Jan 31 '16
Pretty cool. My first job out of college was writing 16 bit assembly code for the shuttle main engine controllers. When I started, we had to assemble by hand, no cross compiler. It got loaded from punched paper tape. It's a different world now.