i am guessing this probe landed yesterday, there is sporatic coverage on the Nasa channel, tapes of the JPL controllers and control center, films of preparations and some animations.
it should get better and there may be some stuff online. i just watched an animation that showed the probe polishing a rock before taking a photo. that probe is relatively huge. --Loren
there is a live news conference on now, dunno if the hi-gain link came up, but one question was about any speculation at to why the EU probe failed.
the response was that ...if anything we (usa) observed applies, there were hi winds aloft...that introduced a 'pendulum type occillation' of the landing vehicle.
now they are talking about, "killer dust storms". --Loren
the current live broadcasts say that the hi-gain is ok.
one interesting data for an old MSC retread is the often mentioned "no-op", no operation, as a method to simply verify command functions.
in 1967, that was an actual command in the 3-C computers that ran the Lunar and Appolo simulators. surely a coincidence, but maybe not for the nomenclature. --Loren
Yep, Spirit landed on time and on target. The NASA website has some pictures downloaded from the lander. B&W so far, but some color shots should be coming down tonight.
It weighs 400 pounds (on Earth) and is about the size of a golf cart.
that was a method used by Floating Point Systems in the 70s & 80s, but i was thinking more of a "NASA" idiosynracy, if indeed that is what this is. Bldg 5 at the MSC (later Johnson) housed a massive (for then) computer complex of both digital and analog machines. mission controllers to astronauts trained on them.
a common "test method" was to insert a no-op directly into memory from the computer console. this would modify various conditions that were being simulated. one nitwit operator even included, "No-Op programming experience" on his resume.
JPL is, of course, or has been, a separate culture. i just thought it remarkable to hear them using the word so many times in last nites' live coverage. it made me laugh to think back about that operator and his, "qualifications". --Loren
In my youth, I spent a few months as a bench tech debugging minicomputer disk controllers. We had the source code to the diagnostic program and we ran it under a debugger. The programmers left big stretches of nops between tests where we could code in "scope loops". Sort of the opposite of what you're talking about?
as a technician, i never really became familiar with many of the "no-op" procedures. one that i remember using gave the lunar lander unlimited fuel, needed when we were trying to troubleshoot problems in the "LEM". in those days, it is likely that we simply overwrote a decrement instruction, or i may dis-remember. some procedures required putting a constant into memory (often 0).
scope loops are a distant memory, along with improvised trigger logic done on the spot. FE's often bragged about how they had to jump these hoops to fix problems that skunked the site CE. we normally inserted a branch to a free area of memory, often with a "status" change when pre-empting an interrupt routine.
we had "automated" equations, and unused gates were listed, so it was feasible to find an existing gate or two, some were published. often, tho, you just inserted a logic card into an used slot. sometimes you needed more than a single card, rare, but memorable. logic analyzers made these gyrations less common. --Loren
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