Here's my #introductions...
Isn't the world a lovely place but in a fine old state though?
Z80 vs floating point (185 words)
things i have learned while figuring out how to implement floating point on the Z80:
fast division (ie multiplying by reciprocal) is only fast if multiplication is much faster than slow division. if you have to do 3 multiplies in the course of it and your multiplies turn out to be 1000 cycles each, long division taking 1800 cycles starts to look pretty damn good
if possible, do slow division with the whole divisor at once. for much the same reason: trying to piece together a 64/32 divide from a 32/16 divide is slow unless you have 32/16 divide instruction, even if you're Roedy Green; it's much easier to make a 48/24 divide from a 32/24 divide
everything gets horrible unless you can fit everything into a single bank of Z80 registers - so 24x8→32 and 32/24→8r24 are probably optimal
you'll feel much better about Z80 cycle times if you divide them by 3½ - assuming an even balance between opcode reads (4 cycles) and data memory accesses (3 cycles); that sort of makes them comparable with 6502 cycle times
A catalogue of mathematical formulas involving π, with analysis
Article by David H. Bailey
In collections: Basically computer science, History, Lists and catalogues
This paper presents a catalogue of mathematical formulas and iterative algorithms for evaluating the mathematical constant π, ranging from Archimedes’ 2200-year-old iteration to some formulas that were discovered only in the past few decades. Computer...
"Times New Roman, size 12 font, 1.5 spacing, like a human being"
"Stone cold auto Calibri 11. I don’t know why I live this way"
- font wars, as reported at
via link love: language at
See also the nearby Typographic illusions:
"as 1929 turned, and unemployment rose to 25% and cardboard shantytowns sprang up, mainstream opinion was that capitalism had irrevocably failed, and representative government would fail too — that the '32 election held off revolution, but when the economy continued to collapse, the revolution would follow. The only question was what kind of revolution. Many believed that "we may be fortunate if we get the American Mussolini"; those out of work held that "all roads lead to Moscow".
Ursula K Le Guin, on tech workers:
"Real power goes to waste. Every wizard uses his art against the others, serving the men of greed. What good can any art be used that way? It's wasted. It goes wrong, or it's thrown away. Like slaves' lives. Nobody can be free alone. Not even a mage. All of them working their magic in prison cells, to gain nothing. There's no way to use power for good."
- "The Finder", from "Tales from Earthsea"
Like to read informative talks with funny slides? Try Idle Words by Maciej Cegłowski
Legends of the Ancient Web
Notes From An Emergency
Build A Better Monster
Who Will Command The Robot Armies?
Superintelligence, the Idea that Eats Smart People
Remarks on the Moral Economy of Tech
What Happens Next Will Amaze You
Web Design: The First 100 Years
For a break from the events swirling around us. I've really enjoyed Fabien Sanglard's series writing about ports of "Another World" to various platforms. I find it somehow relaxing. The latest is on the Jaguar:
The others can be found on the home page:
I never played the game (I saw people playing it in college), but Sanglard's writing about it definitely made me appreciate the work behind it. I want to boot an emulator and play it sometime.
Housebound advice from a long-term housebound person, boosts ok
I'm going to post a long thread on how to cope better if you're stuck indoors at the moment. I've been housebound by disability for a long while now, and sporadically housebound due to depression and agoraphobia before that. These are things that have improved how I deal with that. This is not gonna make houseboundness painless for you but it might help you cope. Disabled comrades are welcome to share their own advice to this thread.
"Okay, here's the scenario. You are a crew member on a starship."
"Space travel is slow, you'll be stuck with your crewmates a long time."
"So we must get along."
"Yes. Communicate, listen, share limited resources."
"I can do that. What's the starship called?"
#MicroFiction #TootFic #SmallStories
Got an old Pascal S compiler to compile and run under RISC OS. Then I read about Pascal S on the web (the compiler helpfully includes no documentation) and discover that Pascal S is a toy subset of Pascal. No pointers, no file IO, or function parameters...
No wonder nobody bothered recompiling it for 32bit RISC OS....
But that's OK because I learned a little about the history of Pascal. And about the .... unique architecture of the CDC6600.
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko