9 ms·
"Ed told me that that software dump has been completed, and it's 'just a matter of time to determine which bit is flipped.'" Can they not just diff it?
by tylerritchie 16y ago
"Ed told me that that software dump has been completed, and it's 'just a matter of time to determine which bit is flipped.'"
Can they not just diff it?
- joeyh 16y agoAgainst what, Voyager 1? :) They've got a live memory image, tracking down a possibly bad bit is probably not trivial. Given the era the code was written there could be self-modifying code in there too.
- knite 16y agoAgainst the original binary uploaded to the spacecraft, I would hope.
- mturmon 16y agoThey've got to be simplifying this a lot for the sake of making a press report understandable. They don't even know there's only one bit flipped. If there is one, they will have to do some analysis to figure out that it would really cause the problem.
- jared314 16y agoI wonder if they have a Voyager VM.
- InclinedPlane 16y agoEven if they did, it might prove challenging to feed it exactly the same input as Voyager 2 itself in order to ensure it's in the same state.
- InclinedPlane 16y agoI'm going to presume that they know what they're doing rather than pretending I know anything at all about operating a 30 year old interplanetary spacecraft. What I would guess is that it's a bit tricky to "just diff" an entire live memory dump (voyager doesn't have a hard drive, just ram and a no longer used tape drive), they basically need to debug the whole thing and figure out exactly what code lives where in memory, down to every last bit. I imagine this might be a non-trivial task.
- eru 16y agoAnd they need to figure out which errors are critical. Some of the bits might be flipped without causing any damage.