To listen to more of W Daniel Hillis’s stories, go to the playlist: • W Daniel Hillis (Scien...
Born in 1956, US inventor, scientist, engineer and visionary W Daniel Hillis pioneered the concept of parallel computers and co-founded Thinking Machines and Applied Minds, which marked a new era in computing and established Hillis as a computing legend. [Listeners: Christopher Sykes and George Dyson]
TRANSCRIPT: Years later when I was at MIT and knew how to program computers I got a call from the chemistry department. And they were still using this thing. But what had happened was I didn't really know how to make a random number generator, I just made it up. And so I had written it in a way that it finally got into a loop where it kept generating the same random number over and over again. And so every time they tried to turn it on it said, 'Sorry, honey, I have a headache', and it would turn itself off. And so I felt very guilty about this so I volunteered to go down to fix it. But of course I hadn't documented anything. I had no idea how this thing worked anymore. All I had to do was find the part where it did that and sort of skip over it.
But I didn't have any listings of the code, so what I would do is I would put a halt and I would put a halt instruction and start it up and see if I could get to the halt instruction before it got to that. So I would sort of by binary search find the place where it did this. But so it means that I had to over and over again start up this computer. But I didn't really remember how to start the computer and all that was left was this set of instructions that I had left for this graduate student which everybody had been following since then. And I knew that most of them were just silliness, causing her to jump through hoops. But I didn't remember which parts were. So I was sorted of hoisted on my own petard. I had to over and over again go through this list, I didn't have time to figure out which parts of it were real. Over and over again turn the machine on and off until I found the instruction to fix.