kens

27 ms·

511.
by kens 2y ago
It looks like the <code> tag is the problem. I guess the Android Chrome code font doesn't include those special characters. I took out the <code> tag and now the characters render on Android (at least for me).
512.
by kens 2y ago
> It's because someone submitted it and more people voted on it. Well, I can't argue with that :-)
513.
by kens 2y ago
No, I don't have any access to internal design notes. But looking at the layout, it's clear that they went to a lot of work to optimize it.
514.
by kens 2y ago
There's more to the story of the Centronics printer connector. Centronics was a subsidiary of Wang Laboratories, producer of Wang word processors and computers. They had 20,000 surplus connectors from one of their earlier calculator pr
515.
by kens 2y ago
Most of the rest of the information is from various web sources (see the references in the footnotes). One source that might be interesting to others is the National Archives Catalog https://catalog.archives.gov/ which has
516.
by kens 2y ago
Almost, the hammer strikes the ribbon and the front side of the paper. The drum is behind the paper.
517.
by kens 2y ago
You'd think that hammering the paper against the spinning drum would result in a blurry mess at best, but the hammers are fast enough that it works. It's the same principle as a chain printer such as the vintage IBM 1403, where th
518.
by kens 2y ago
I'd like to dump the ROMs, but they are soldered in and covered with conformal coating, so it would be moderately destructive to remove them and dump the contents.
519.
by kens 2y ago
The printer took a big roll of paper, maybe 5 inches in diameter (although I don't have it here to check). I was a bit surprised that they didn't trim the roll down to the minimum size necessary, but just used a full roll. I guess
520.
by kens 2y ago
I don't know why this popped up on HN after four years, but author here to answer your questions...
521.
by kens 2y ago
No radiation hardening. Their main priority was building a system in 7 months that meet their toxicity and flammability standards. The original military teleprinter weighed 100 pounds. They cut it down to 59 pounds, so that's a win, I
522.
by kens 2y ago
It's loud enough that NASA put acoustic down in the locker for the printer. But it's not screeching like dot matrix.
523.
by kens 2y ago
NASA had toxicity and flammability constraints that limited what they could use.
524.
by kens 2y ago
I had to go to the Library of Congress to get some of the information...
525.
by kens 2y ago
Author here if anyone has questions...
526.
by kens 2y ago
Thanks for your reply. For background, I'm doing technical/historical research. I have 100 documents on a topic (mostly PDFs, also some scans) and I want to keep track of them, pull ideas out of them, and write a coherent article.
527.
by kens 2y ago
I've been using Obsidian for a few weeks. It fits my note-taking style (Markdown and wiki) and I want to like it, but honestly it's a struggle. My main issue with Obsidian is the steep learning curve because Obsidian is not self-c
528.
by kens 2y ago
I'm researching the Minuteman II's computer, the Autonetics D-37B/C so I figured I'd put a note here in case there is anyone else looking at it.
529.
by kens 2y ago
I use an AmScope ME300TZB-2L-10M metallurgical microscope that I got for cheap on eBay. My friends all have cooler microscopes :-)
530.
by kens 2y ago
Yes, looking at IBM stuff is like being in a parallel universe where everything you take for granted is slightly off. You have token-ring instead of Ethernet, you have SNA (or something) instead of TCP/IP. Characters are EBCDIC, not AS
531.
by kens 2y ago
How did I get into this? It started when I saw the simulation of the 6502 processor from the Visual6502 team [1]. It was very cool, but totally mysterious. I realized that even though I was a programmer and understood the "full stack&q
532.
by kens 2y ago
Thank you to you and all the others in this thread for your positive comments. I almost didn't write about this chip because it is so obscure, so it is encouraging that people are reading it.
533.
by kens 2y ago
We haven't been able to get old information from IBM; either they discarded it or don't make it available. There are lots of old manuals on bitsavers, which is a treasure for historical computer research. It is worrisome how much
534.
by kens 2y ago
I looked at a random 7400-series die and I think the feature size is about 5 µm. (The width of the thinnest metal and silicon features.) Bipolar chips have different construction from a MOS processor, so the features aren't directly co
535.
by kens 2y ago
The feature size on chips has steadily shrunk from 10 µm for the Intel 8008 to a few nanometers nowadays. The feature size is determined by the limits of contemporary technology, which steadily improves as described by Moore's Law. Man
536.
by kens 2y ago
Author here if anyone has questions...
537.
by kens 2y ago
The well-known linguist John McWhorter argues that Shakespeare's plays should be translated into modern English since they are written in a language that we effectively no longer speak. "Indeed, the irony today is that the Russian
538.
by kens 2y ago
Kahan was the co-architect of the 8087. Palmer (at Intel) hired Kahan as a consultant for the 8087 since Kahan was an expert on floating point. Kahan says: "Intel had decided they wanted really good arithmetic. I suggested that DEC VAX
539.
by kens 2y ago
Yes, your edit is correct.
540.
by kens 2y ago
That NASA article kind of misses the point. NASA uses 15 digits for pi because that's the default and it is enough accuracy for them. The interesting question is why is that the default. That goes back to the Intel 8087 chip, the float

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