Earlier quoted context omitted.
"Some programmers nicknamed the finished product LOL memory, for Little Old Lady memory." LOL.
In 1967, binutils was a person.
Huh? I don't get it.
Apollo program source code
51–60 of 60 posts
Re: Apollo program source code
#52Earlier quoted context omitted.
Just curious how they knew this given how young the computing industry was at the time that this was used. Were there some "Well, that's interesting..." moments where we launched something and realized it was affected by cosmic rays?
I think it's just an understanding of how the underlying physics work. Alpha and beta radiation will cause bits to flip in solid-state devices, because the state is held with electrons. Whereas core rope memory stores that state as magnetic fields in ferrite cylinders. So radiation will basically just bounce right off the giant ferrite cores (giant relative to solid-state semiconductors, that is). *I am not a physici…
Its more a cause of the radiation ionizing the underlying semiconductor material. For instance when an electron tunnels into a transistor it can cause strange effects. Look up single event upset and single event latch-up for more information. The SEL is interesting as it causes a transistor to act as a double transistor and start drawing tons of power. At least that's how I understand it.
Re: Apollo program source code
#53Earlier quoted context omitted.
In 1967, binutils was a person.
Huh? I don't get it.
Binutils are a set of utilities used by *nix systems.
Re: Apollo program source code
#54Re: Apollo program source code
#55Earlier quoted context omitted.
Just curious how they knew this given how young the computing industry was at the time that this was used. Were there some "Well, that's interesting..." moments where we launched something and realized it was affected by cosmic rays?
Hubble, the ISS and other low-orbit satellites are affected by the South Atlantic Anamoly, which funnels down charged particles from the Van Allen belts. (This /was/ a surprise to the folks who designed Hubble, but the spook satellite people apparently knew all about it . . . and didn't tell the Hubble folks, not even over beer or something. Great win for national security, guys ).
I didn't see an opening bracket for sarcasm so I assume it's before 'Great win'. Were they really surprised by this? Also are they same people that didn't know putting hard drives in space would fail because of the lack of air and had to replace them with SSDs?
Re: Apollo program source code
#56Earlier quoted context omitted.
Huh? I don't get it.
the person who builds the core rope memory
Aha. Binutils = compiler, linker, weaver, ....
I think this is one person who can legitimately say that he programs with a magnetized needle and a steady hand. http://xkcd.com/378/
Re: Apollo program source code
#57Here is my implementation of the Apollo 11 computer in verilog on an FPGA:
https://github.com/donnaware/AGC
It has an assembler and IDE.
Re: Apollo program source code
#58Earlier quoted context omitted.
Just curious how they knew this given how young the computing industry was at the time that this was used. Were there some "Well, that's interesting..." moments where we launched something and realized it was affected by cosmic rays?
I think it's just an understanding of how the underlying physics work. Alpha and beta radiation will cause bits to flip in solid-state devices, because the state is held with electrons. Whereas core rope memory stores that state as magnetic fields in ferrite cylinders. So radiation will basically just bounce right off the giant ferrite cores (giant relative to solid-state semiconductors, that is). *I am not a physici…
Hmm, it's more like any ionizing particle (charged) creates pairs electron/hole, many of them, so that the charge distribution in the pn junctions are altered. Sometimes gamma photons generate Compton electrons in the material that act as delta rays, to the same effect. Heavy particles can alter the crystal structure, inducing defects that may change its properties. Magnetic storage devices don't have polarised junctions and could withstand all this if they didn't include solid state electronics. Radiation hardening techniques and shielding can help a lot.
Re: Apollo program source code
#59Earlier quoted context omitted.
Bugger is not common slang in American English. You can find people who will argue about that, but they don't get out much.
I've used bugger since the first of the Austin Powers movies. My friends and I used it until one of them married a South African girl and she made us stop being as it was incredibly impolite and rude apparently. I started again last year after watching Top Gear and then recently got yelled at by a new accounting manager who moved into the office across from my cubicle. Once again, I was being crude but in all honesty…
Very commonly used in New Zealand, its used on TV with no problems, heres the iconic Toyota ad using the word bugger to good effect: http://www.youtube.com/watch?v=TKY_OysWu3k
Re: Apollo program source code
#60Fun fact: the actual programs in the spacecraft were stored in core rope memory, an ancient memory technology made by (literally) weaving a fabric/rope, where the bits were physical rings of ferrite material. http://en.wikipedia.org/wiki/Core_rope_memory
Related: Magnetic Core Memory, the read/write version of Core Rope Memory. http://www.corememoryshield.com/report.html