kens

8 ms·

91.
by kens 6mo ago
The short answer is that it shows what one can get people to believe through relentless self-promotion. For a longer answer on the first microprocessors: https://spectrum.ieee.org/the-surprising-story-of-the-first-...
92.
by kens 6mo ago
I couldn't find the specification for the Angle Computer, but I've found specifications for other devices and you're exactly right: pages and pages of vibration requirements, fungus resistance, testing procedures, and then ma
93.
by kens 6mo ago
No, it needed to lock onto the right star, the one that matched the coordinates. Otherwise, it would be pointing in a random direction. The navigator would check against three different stars to detect an error. The system could also use pl
94.
by kens 6mo ago
It's totally normal to be in the northern hemisphere and looking at stars below the celestial equator. For instance, Sirius is the brightest star in the night sky and is in the southern half of the celestial sphere. So if you wanted to
95.
by kens 6mo ago
I'll probably write another article on the star tracker itself. But I can give you a quick summary of the spiral search mechanism. It was electromechanical: a motor turned a resolver, a device with coils to generate sine and cosine fro
96.
by kens 6mo ago
> First microprocessors in jet fighters Don't get me started on that...
97.
by kens 6mo ago
If you're flying in low latitudes, nearly half the stars that you want to use are going to have negative declination, so negative declinations are important. As for the hemisphere switching, this happened automatically.
98.
by kens 6mo ago
No, it did not provide ground track. You could manually produce a ground track using the line of position technique described in the article.
99.
by kens 6mo ago
We couldn't find a wiring diagram so I had to trace out every wire.
100.
by kens 6mo ago
The device has a spiral search mechanism to find the star. Then it locked onto the star and automatically tracked it. So this was unlike the Apollo star tracker where the astronaut has to manually aim at the star.
101.
by kens 6mo ago
Author here if you have questions about this analog computer...
102.
by kens 6mo ago
I'm here if anyone has questions on the AP-101 computers or the 4 Pi family...
103.
by kens 6mo ago
I'd like to study aerospace systems from other countries. Unfortunately, it's even harder to get information on foreign systems than US systems.
104.
by kens 6mo ago
It's easy to get the military round connectors from Digikey; it just isn't cheap :-) eBay is your best bet for an affordable price on them.
105.
by kens 6mo ago
Actually I'm mistaken; the AWACS CC-2E computer was also a redundant dual processor system.
106.
by kens 6mo ago
The E-3's computer was definitely heavy: the brochure that I have says that it weighed 1,826 pounds. (There's a nice photo of the refrigerator-sized cabinet full of circuit boards in my article.) The 4 Pi line is kind of strange;
107.
by kens 6mo ago
You're right, that's BS :-) Yes, many of the 4 Pi systems were essentially IBM 360 mainframes; some were completely compatible, while others were more "inspired" by the 360. However, only the little-used EP/MP model
108.
by kens 6mo ago
The name is essentiallly a geometry joke. The IBM System/360 line of mainframes (1964) revolutionized the computer industry with the concept of one family of computers for all applications: business and scientific. (Before the 360, nob
109.
by kens 6mo ago
Author here: I've finally finished a detailed history of IBM's 4 Pi computers, powering everything from the B-1 bomber to the Space Shuttle. Let me know if you have questions...
110.
by kens 7mo ago
Oh, I see the difference now. In the photo of the IBM 2260 terminal that I used, the bezel is rectangular and flat. In every other photo of the 226, the bezel is sunken and the screen is oval-shaped. I'll ask around and see if I can fi
111.
by kens 7mo ago
The manual for the IBM 2260 describes the CRT in detail but I don't think it has the information you want. My guess is that if you're IBM, you can get the CRT in whatever shape you want. [1] https://www.bitsavers.org&#x
112.
by kens 7mo ago
Like I need another big project :-) The IBM Datamaster is an interesting system, but it was doomed. It had an 8-bit Intel 8085 processor, cost $9000, and came out in July 1981. The IBM PC had a 16-bit 8088 processor, cost $1565, and came ou
113.
by kens 7mo ago
The article asks about the etymology of X for crystal. I looked into that a while ago. The abbreviation "xtal" has been used for "crystal" since the 1800s in medicine, geology, and chemistry, and then electronics copied
114.
by kens 7mo ago
Taste has a much longer pg history: "Taste for Makers" in 2002, "How Art Can Be Good" in 2006, and "Is There Such a Thing as Good Taste" in 2021. (If we're venting about words, I'll bring up "opi
115.
by kens 8mo ago
Did someone ask about Intel processor history? :-) The Intel 8080 (1974) didn't use microcode, but there were many later processors that didn't use microcode either. For instance, the 8085 (1976). Intel's microcontrollers, su
116.
by kens 8mo ago
Is there a tool or something that gives this vibe check? (Serious question)
117.
by kens 8mo ago
AMD's Am9511 floating-point chip (1977) acted like an I/O device, so you could use it with any processor. You could put it in the address space, write commands to it, and read back results. (Or you could use DMA with it for more p
118.
by kens 8mo ago
The ROM in the 8087 was very unusual: It used four transistor sizes so it could store two bits per transistor, so the storage was four-level. Analog comparators converted the output from the ROM back to binary. This was necessary to fit the
119.
by kens 8mo ago
If you have a child, you should definitely check out FIRST, started by Dean Kamen, who also invented the Segway. For elementary students, FIRST LEGO League uses simple, LEGO-based robotics. In high school, FIRST Robotics has the students bu
120.
by kens 8mo ago
The microcode is protected by copyright; see NEC Corporation v. Intel Corporation.

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