"Target demographic: Commies." "Just a minuteman". Thanks, I needed a laugh. That was just the right placement of wry wit.
A lot of folks tend to honor the Osborne 1 as the world's first mass-produced portable computer. The machine was admittedly an early pioneer in totable systems in 1981, but another, much-earlier computer perhaps really deserves the credit. This old box logo Some 20 years before the Osborne's release, the American government …
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It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the missile from a position where it is to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position that it was, is now the position that it isn't.
In the event that the position that it is in is not the position that it wasn't, the system has acquired a variation, the variation being the difference between where the missile is, and where it wasn't. If variation is considered to be a significant factor, it too may be corrected by the GEA. However, the missile must also know where it was.
The missile guidance computer scenario works as follows: because a variation has modified some of the information the missile has obtained, it is not sure just where it is. However, it is sure where it isn't, within reason, and it knows where it was. It now subtracts where it should be from where it wasn't, or vice-versa, and by differentiating this from the algebraic sum of where it shouldn't be, and where it was, it is able to obtain the deviation and its variation, which is called error.
And that is how missiles work. Simple, eh?
"....but how many computers do you know that can destroy the world?...."
Bearing in mind their demands to have him extradited and tried in the USA, I hereby nominate Gary McKinnon (or rather, his computer) as a contender for a "World - Ender" award. Well, OK, maybe just a "Nearly, but not quite, "Ended -The-World award". It kinda reminds me of this....
Anyhow, back to the story. I wonder: if it didn't have a screen, would it never suffer the BSOD? Surely a plus point and another reason to celebrate this upwardly mobile computer. Death and destruction notwithstanding.
"So, I take it this was the granddaddy of the famous Saturn V instrumentation unit"
Yes and no. IBM built the guidance processor for Saturn.
As for the layout. All missiles aim to minimise unnecessary weight. So any pressurised structure usually has a round end. This ranges from c 17 psia on Saturn 1 tanks to 100s of PSI for something like a solid. Unless you want to expose that end to launch heating and balence the payload section on the extreme top you'll be wrapping a ring round it. Logically you'll suff the guidance sensors (Black Arrow did not have a guidance computer), computer and fine guidance fuel tanks here(Modern ICBMs usually have a liquid last stage to fine tune the trajectory). This allows 1 coputer to run the whole show. Ariane does the same and Aries will as well.
Mine's the one with a compu of the Saturn IU manual in it.
Firstly, to Austin: Great article! You had me laughing out loud, while immensely enjoying the nostalgic elements of the article. Wit and humour--with a touch of relevance--is precisely the reason I read the Register daily.
@AC: "The missile knows where it is at all times"
@A.A.Hamilton: "50% less mutual?"
No, it works well as 50%. If mutual is comprised of precisely two parties, then "50% less mutual" technically means "unilateral", which is follows the intent of the author. I say "technically" because semantically "mutual" is one of those concepts which are absolute, like "perfect" or "unique", which something either is or is not, wholly.
@AC--presumably Mr. Modine alludes to the anthropologist Ruth Benedict's book _The Sword and the Chrysanthemum_ a study of Japanese culture published about the time of the Great Patriotic War. It is fair to say the preferred metaphor in the west is probably "plowshare" from the Bibilical "they shall beat the swords into plowshares". As I recall, there was a Project Plowshare in the states, aimed at civilian uses of nuclear energy.
As it says in the Camel Book, at the end of the section on "for" loops:
"If the notion of infinite loops bothers you, we should point out that you can always fall out of the loop at any point with an explicit loop-control operator such as last. Of course, if you're writing the code to control a cruise missile, you may not actually need an explicit loop exit. The loop will be terminated automatically at the appropriate moment.*" And, when you follow the star: "* That is, the fallout from the loop tends to occur automatically."
(Larry Wall, Tom Christiansen and Randal L. Schwartz.)
Kept me reading all the way through prolly could of done another 12 pages and i would of read them.
Needed bucket o' Sunshine somewhere in there even if somebody else coined the phrase !
Personally i think that phrase should be used in every conversation regarding nukes.
@They were never actually used, how do we know they were any good?
"After a successful initial test flight in 1961, the US Department of Defense formally green lighted the Minuteman program. The missiles turned out to be a big hit, although thankfully never literally."
"The on-board system navigated by measuring velocity with gyroscopes and acceleration with an accelerometer - sort of like a Nintendo Wii controller, only slightly more deadly when you accidentally toss it at your television set."
this one is now splatered in cornflakes and milk......
Austine, you're not a Journalist, you're a comedian...
Brilliant article - your dry humour, apart from being very funny, simply melts the face off the insane mindset of these dinosaurs. How long will it be before everyone who has dedicated their working life to weapons will be held in similar shit-eating lunatic contempt?
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It's interesting that 60 years on the principle of inertia guidence this uses is now concidered advanced in the Wii controller.
Inertia guidence and GPS will be in camera phones next, allowing you to wave your camera arround to obtain a 3D Google Street View style photo. That's looking 1 year ahead if that.
What do the military have right now that will be in our hands in 60 years time?
Excellent article, big up The Register.
Many of these were given to colleges when they were retired, and there was a livley exchange of hacking tips, distributed as mimeographed newsletters. Many students got their first exposure to embedded computing from these systems.
I/O, IIRC was 5-level TTY input, Servo control output. Many of the early questions were of the form "How do I get human-readable _output_?"
Linux? Um, the Linux kernel is written not in ANSI/ISO C, but in gcc (A dialect, in the sense that Norwegian is a dialect of Swedish, or Bosnian of Serbian) gcc does not believe 24-bit computers exist.
Not to mention that /bin/true (even on an older FC4 system) is larger than this system's total memory, even when dynamically linked, and stripped.
Nice article indeed.
But something on the pictures to give a better sense of the size of the thing would have been nice. It says that the computer weighted 60-something pounds, but it look like something much heavier. Was it a typo for 600-something, or is the impression of big size just an illusion?
A very interesting read. I never really thought about how guided missiles go about their business until now. fascinating to think these things carried about an entire prehistoric computer system. It's pretty amazing what innovation and creativity can spring out of a Cold War scenario, eh..?
"The Minuteman 1's missile guidance computer was a bleeding-edge 24-bit microcomputer made by Autonetics Division of North American Aviation."
Autonetics Division of North American Aviation. A subsidiary of North Central Positronics no doubt.
Great article, and the usual great comments, this one not withstanding.
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