Aaron Sawdey, Ph.D.

Ph.D. EE, core performance model hacker (IBM z), space geek, alldogmn.org dog foster,  LeechLakeLegacy.org  board member, photographer, he/him, opinions are mine not my employers

Spouse: Merry Obrecht Sawdey (npub1ysg…gwr6)
Verification: https://www.leechlakelegacy.org/about-us/leadership/

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Last Notes

2026-09-21 04:07:04 UTC

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Yeah kind of like Isaacman’s private air force which includes a MiG-29. That’s just standard billionaire shenanigans these days though.

2026-09-21 03:52:27 UTC

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The FAA registration is odd reading.. the engine is classified experimental/exhibition? It is funny to me to be able to look up the N number of a fighter.

2026-09-16 05:17:23 UTC

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so very pointy… bringing back memories of the X-3 Stiletto

2026-09-09 11:52:27 UTC

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We have instructions for that, as he says. If the code is in any idiom the compiler can recognize as “swapping byte order” it should turn out fine. There is very little IBM power BE Linux any more, after POWER8 came out with good support to do LE, all the major distros supported it. At this point they’ve all discontinued BE.

2026-09-09 11:45:09 UTC

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I’ve always thought protobufs was cool but this seems much more practical. If I understand it, it generates c++ code for the structure to be interchanged?

2026-07-06 18:42:10 UTC

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exactly. And as a concept, they’re always there, even if you’re using a language that hides them. Get deep enough into debug or performance and you need to know what those language constructs actually do.

2026-07-06 18:38:56 UTC

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Also by the time you can deal with complex data structures in C … you gain a deep understanding of exactly what pointers are. Not trivial to new learners of languages. Also essential if you want to get anywhere with the toolchain and how ABIs work. Like you said .. built the world.

2026-07-02 04:46:08 UTC

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Radio on your walking stick tuned to the air freq so you get a little warning who is next running the low level route? We certainly enjoy the things you catch out there waiting in the sun and rain.

2026-06-19 20:56:44 UTC

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diy Schlieren imaging of stuff passing in front of the sun is such fun!

2026-04-21 17:40:18 UTC

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So they're not highly motivated to escape is what you're saying ...

2026-04-21 17:39:21 UTC

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I'd expect your average cat would just climb chicken wire .. I've seen people construct completely enclosed "cat runs".

2026-04-08 15:19:46 UTC

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I thought that was a thing that had been tried occasionally? It wouldn't be fast on an old 8-bitter but you could implement a strong ECC layer to correct errors from a received tape which then wrote out a program tape you could then run.

2026-03-11 20:42:01 UTC

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wasn’t there a competition to make a prototype of a space elevator climber that used beamed energy, either optical or microwave? Completely opposite of omnidirectional of course.

2026-03-04 20:55:16 UTC

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That whole experience looks fantastic.

2026-03-04 12:41:25 UTC

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Nothing is very fireproof once fluoride enters the chat. Oxygen, well it’s all about the temperature. But somehow I don’t see that making houses out of inconel is going to catch on. Very large wood timbers have the advantage that they char on the outside somewhat like an ablative heatshield. End-grain oak has been used as a re-entry heatshield.

2026-02-26 23:06:50 UTC

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The progressive/left nature of librarians and library boards should not be discounted ...

2026-02-22 16:06:27 UTC

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I’d worry most about the company of other horses, they are really happier with hooved friends around. I’m guessing they have hay and water in the little covered structure, that enclosure couldn’t feed a horse for more than a few days on the grass. Ok cool the horse is ok, thanks! (Work in animal rescue for a while, worry about a random horse in a picture I guess 😂)

2026-02-22 15:51:14 UTC

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So I hope the horse wasn’t one of your terrible neighbors… maybe just belonged to one. Having a small horse paddock in the middle of a neighborhood of this density seems odd to my midwestern USA eye — here typically you can’t have horses unless there is quite a bit more open space. Best of luck in your new space!

2026-02-19 19:45:25 UTC

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Station wagon figured in my learn-to-drive experience in that the (required) HS "behind the wheel" class was taught using 70's Caprice station wagons. So while I learned the basics on country gravel roads in a tiny civic, then I get put behind the wheel of this power-automatic-everything land yacht which was slightly hilarious.

2026-02-19 04:05:48 UTC

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I have fond memories of a 1986 Accord 4-door I got for $900 (pop up headlights and stick shift!). I fixed all the deferred maintenance issues and passed it on to a relative after a couple years. It had a 2bbl carb which surprisingly was never an issue.

2026-02-19 04:01:56 UTC

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yeah I remember that thing, it was crazy. But in reality a swap to a b18 (or nowadays a K20) is plenty. Mine has a 4-2–1 header and plenty of zip .. curb weight is only 2050 lbs. Another upgrade that I’ve thought about is a limited slip differential— you can get a gear type one for the civic transmission. I haven’t driven mine in a couple years because it needs an alternator and master cylinder 🙁

2026-02-19 03:47:56 UTC

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Data point: I drove a 1988 CRX (stick!) up old mining roads in Montana that a local suggested you might want “4wd and heavy tires” .. just needs caution and don’t drive in the ruts as it has no ground clearance.

2026-02-11 01:33:59 UTC

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I’ve never been a coffee drinker either 😂. Mostly because it is unpalatably bitter to me. Obviously I’m not elite hacker material …

2026-02-11 01:30:08 UTC

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good god i had to quit drinking that when I was like 20 because it made me too wired to function. If I drank some now, I should just pre-book with the local ER.

2026-02-04 23:08:25 UTC

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The Hawker Hunter is pretty but also showing off the early jet vibe with small intakes, long pipe, and as many underwing drop tanks as it can manage ...

2026-01-07 22:00:46 UTC

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Somebody's got that v4 tape lashed up to a pdp11 emulator that runs in your browser so you can boot it and try it out!
https://unixv4.dev/

2026-01-01 19:17:30 UTC

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The 1990s equivalent of Mastodon is some combination of gopher server, public domain/shareware base bbs system, and uucp 😂
So if I think of it in those terms I can see his point. It’s the space outside the walled gardens.

2025-12-21 06:23:19 UTC

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when B5 and DS9 were on the air together during their original runs, you could see DS9 copying stuff. Like the welders on the outside of the station in the title sequence. B5 had them, DS9 copied. But yeah, so many throwaway things in DS9 were never followed up. JMS on the other hand had a top secret 5-season plan. So many cool things. Unisex bathrooms on B5, and that single frame sequence in one of the last episodes, you had to tape it and step through it.

2025-12-15 18:46:08 UTC

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The instruction set is just bits. This is all about how you write an assembler to turn text into those bits. Don't like this order? Write your own assembler.

2025-12-15 12:07:10 UTC

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‼️
Amazing bunch of shots there!

2025-12-15 04:45:17 UTC

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Such a neat concept, sad that the scientific basis for it couldn’t compete with cheaper means of doing similar things.

2025-12-13 03:29:09 UTC

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seems like with that RC and the thresholds of the hct14 you should never see anything less than a couple ms between transitions.

2025-11-23 19:21:13 UTC

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we need a new internet for the people who just want to do useful stuff.
Do I recall that the issue was ffmpeg maintainers tired of endless issues filed by giant corps who are using it but not actually helping?

2025-11-17 03:49:42 UTC

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yes, exactly. Spacex knows how to make rockets work, there has never been one that works as well as Falcon 9. And nobody has ever even tried to build something like Starship. There is plenty to criticize about the whole situation without being ignorant about the engineering.

2025-10-18 03:07:57 UTC

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I dig it. Somehow there is now a long association between AC/DC and accessorized bagpipe covers of their music.

2025-09-23 19:45:01 UTC

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I don't consider $4/month just to use a podcast app to be reasonable in any sense of the word. That's Adobe level pricing.

2025-09-23 19:33:53 UTC

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thanks ... that explains A LOT of what is going on ... "sold to Automattic", say no more.

2025-09-23 19:18:06 UTC

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it has recently started looking like this. If you click the X it offers you can make the ad go away for $3.99/ month or $39.99/yr. I’m all for paying for apps but this is ridiculously overpriced.
https://cdn.fosstodon.org/media_attachments/files/115/255/219/471/893/021/original/3a3c7a274e47635d.png

2025-09-23 19:03:33 UTC

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The app "Pocket Casts" has added ads and now wants $3.99/month to not see them so I also hope others copy all that's good about it because I for one am looking to leave that app.

2025-09-23 18:58:45 UTC

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Yes. PE bought a nursing home in our small town (5000), then 2 years ago something went drastically wrong with the building (probably deferred maintenance), they moved the patients elsewhere, and now it's an empty eyesore that takes town resources to police, and the city council can't get the owners to respond at all. There's talk of demolishing it and charging their property tax bill because at least they're paying THAT.

2025-08-21 23:25:57 UTC

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I mean, what’s the difference between an LLM’s hallucinations and what a compiler does with your code after if proves to itself you have committed UB?

2025-08-21 23:23:28 UTC

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would also give compiler developers a ready made excuse for some of the more bizarre wrong-code bugs

2025-08-17 23:41:17 UTC

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I guess darkside doctors take the Hypocrite oath? Because I don't see how helping the insurance companies this way is "do no harm".

2025-08-10 05:08:49 UTC

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I hope it doesn’t come to it but there is always “the net treats censorship as damage and routes around it” — I’m not a libertarian, but you can’t piss off this many furries and trans folks and not provoke some kind of reaction

2025-07-31 19:05:26 UTC

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Buy two year old phones on eBay? the depreciation curve is pretty darn steep.

2025-07-24 23:24:18 UTC

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Normalize hotel and conference room Ethernet jacks 😎

2025-07-24 23:10:26 UTC

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Not even just satellite .. also WiFi. Which only mostly works.

2025-07-06 17:46:55 UTC

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Indeed. The folks who do the farm work at my local CSA are some of the most wholesome people I've ever met.

2025-06-26 03:46:16 UTC

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areal as in atypical? Works.

2025-06-14 18:58:38 UTC

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Can you still get things like 74HCT/74AHCT that are CMOS but use 74xx TTL logic thresholds for maximum compatibility? Those were great in the late 80's for cleaning up crappy TTL signals because their outputs are rail-to-rail.

2025-06-14 18:00:18 UTC

#NoKings #dogsofmastodon
Dogs of the resistance.
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2025-05-29 03:00:17 UTC

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Is that a 738-200 with JT8Ds?

2025-05-22 19:20:59 UTC

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That is a lovely piece of composition.

2025-05-18 13:31:16 UTC

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some people think they’ll become famous influencers on bsky but not many people join fedi for that.

2025-05-11 12:42:23 UTC

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Somewhere, someone will have written some assembly code optimized by making use of this property 😂

2025-05-01 14:52:28 UTC

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I mean, people have been writing papers about how poor the end-to-end efficiency of corn ethanol is since at least the 1980's.

2025-04-20 17:43:45 UTC

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so .. this can in theory register any combination of keypresses .. nice. I suppose the routing is why more keyboards don’t work this way.

2025-03-17 01:54:57 UTC

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ISRO is developing one, maybe ESA will as well?

2025-03-14 17:31:38 UTC

A couple dozen wild turkeys visited this morning browsing the lawn and woods. The four boys at the back were fluffing and strutting from time to time.
Shot through a window with a Canon FD 200/f4 & Olympus OM-D E-M1
#wildlife #spring #wildturkey
#birds #birdsofmastodon #birding
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2025-03-08 03:01:41 UTC

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What, no love for IRIX on SGI workstations with MIPS processors? 😁

2025-03-02 05:29:51 UTC

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To your original point .. every time I look at one of those turnkey NAS boxes I just see that it has so few bays and some puny processor and network and they want $OMG for it. If money is no consideration and you want something as easy to operate as a toaster, sure go ahead. But for everybody else?

2025-03-02 05:16:44 UTC

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not that many people probably. I got an old supermicro 2U with 12 bays to make mine .. more of a storage server than a NAS. But I paid 10% of that. It has 4x 1G Ethernet…

2025-02-28 02:57:23 UTC

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I have questions about your generation labeling 😂
MMR vaccine combo introduced in 1971. That's gen X territory. I'm older gen X and got measles/mumps vaccines separately and actually had rubella. Have had MMR vaccine twice now since 2000 to maintain immunity. Measles vaccine use starts in 1963 and boomers are through 1964 so most would not have had the vaccine as children.

2025-02-27 16:47:18 UTC

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This is an interesting idea ... I guess you could have a macro with 2 arguments (type and name) that defined the member variable, and get/set functions. That's a great idea for that style of c++.

2025-01-28 21:08:59 UTC

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I can't really say, I was never in any "serious" environments ... grad student, then sort of roll your own non-shipping software environments.

2025-01-28 13:59:45 UTC

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Journaled filesystems helped a lot but that wasn't really data integrity, more like resilience against loss of cached updates when your system crashed. SGI XFS, ext3.
"we're going to need tape. Lots and lots of tape"
<the matrix creates an infinite room of tape robots>

2025-01-27 04:31:18 UTC

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Seems like Tesla is floating on an AI & self-driving bubble, their valuation is not like any other automaker.
The danger is we are seeing articles saying the EV market is not growing, when really what's happening is that Tesla sales quit growing .. incompetent reporting or somebody pushing a message?

2025-01-18 18:02:15 UTC

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you hardly need a full rack for that. I have an old 2 socket 2U Xeon that could probably handle all that given a sufficient internet link. Has 12x 3.5” bays so many TB of disk (I’m using 6x 2tb raid5) .. of course you could have a couple for redundancy.
Totally on board with the goal of self hosting everything possible.

2025-01-02 13:23:33 UTC

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I mean, the other solution is: don’t shave … works for me 😂 🧔🏻‍♂️

2024-12-18 15:40:42 UTC

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did they ... not even go read your instance landing page which basically says "this is vkc's Queendom, there are no other users" ... wow. 🤦‍♂️🤣

2024-12-13 21:58:51 UTC

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Just keep extending it, I want to see a neon sign negotiate for a couple milliamps at 2000V from USB-C PD.
some invention required for the necessary dielectrics to have skinny cables 😁

2024-12-10 04:58:03 UTC

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d(bugs)/dt ?

2024-11-18 16:08:33 UTC

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Could you make such a thing operate in an unlicensed band?

2024-11-04 19:40:05 UTC

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The executive branch isn't being run by someone who is intentionally and unintentionally dysfunctional.

2024-10-23 18:26:05 UTC

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Somebody ought to FOIA that 😎🏎️

2024-10-16 02:20:40 UTC

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Heh, ok that’s clever. I think that probably had implications about the drop you want across D2 if you want Q1 not to be saturated.

2024-10-16 02:06:22 UTC

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I’m not really that kind of EE but I’ll say a shottky diode for D1 makes sense, I guess it’s just to improve the drive for a hi output, so low forward drop is good, you mostly get R1 and R2 in parallel as a pullup. The drop across D2 is going to set the base voltage of Q1 so you want it a little lower than Vbe for Q1 so the transistor is turned on hard. Doing the sim is probably the easiest way to see what all these forward drops are anyway.

2024-09-12 18:36:54 UTC

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Even NASA has been working on magnetic and electrostatic shielding for spacecraft, and some of those techniques would be vastly easier to implement on a planetary surface.

2024-09-11 18:43:15 UTC

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I know from experience you can make a HD 5.25" drive act like an 8" drive because that's exactly what I did with the floppy controller on my zenith z100 .. which could run cp/m :)
I have memories of user numbers from a Kaypro 10 though ... that was not really the greatest way to organize things.

2024-09-07 15:46:25 UTC

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Not much of a picture but it was quite bright, a 3-second exposure shows as a short streak just to the lower right of center here. Motion at 1000km was much slower than for example the Starlink trains at much lower altitude.
https://cdn.fosstodon.org/media_attachments/files/113/097/046/827/996/583/original/491b83f72c486fba.jpeg

2024-09-07 15:41:09 UTC

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I observed it pass over a few days ago and saw slow changes in brightness. That it’s being allowed to tumble explains that. Good to hear it’s according to plan.

2024-09-06 14:17:11 UTC

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Heh, this like me about changing a thermostat on a car engine without draining the coolant .. I mean as long as the bucket you put under to catch what starts draining out doesn’t fill up, right? 😂

2024-09-06 03:21:37 UTC

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Meanwhile compiler folk are like 🤦‍♂️

2024-09-05 00:54:57 UTC

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Looks like they are the SATA version, so no > 512b sector sizes

2024-09-05 00:32:30 UTC

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I’ve been getting them off Amazon

2024-09-05 00:30:20 UTC

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100% behind this, there is a lot of extra engineering that goes into the enterprise stuff. 2TB HGST enterprise drives refurbished for $40 or less is a real steal.

2024-08-29 18:18:15 UTC

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😂 while the 8087 was microcoded and slow by today's standards, back in the day it plugging it into an 8088 machine was like sitting down at a supercomputer.

2024-08-25 13:12:05 UTC

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I mean if it’s x86 I think you don’t need to do anything explicit? Even with ppc that I was working with, if you have a 64b store, other threads either see it or don’t (if you aren’t crossing a cache line). But if the compiler replaces that with multiple smaller stores, you could have a context switch and then it’s partially visible. Sounds like maybe GC looking for pointers was involved?

2024-08-25 05:04:11 UTC

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From the point of view of a compiler guy … 99% of programs do use normal libc, and there is so much legacy code out there with stupid little memcpy routines somebody wrote that are now slow compared to what the compiler can generate inline or libc memcpy. I apologize for people who actually know what they are doing getting zapped but this is why we do it.

2024-08-09 20:04:32 UTC

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I don't know if you recall the history but at the time those contracts were awarded, the SpaceX one was an afterthought. There were factions at NASA and in congress who thought it ought to be awarded to Boeing only.

2024-08-09 03:35:04 UTC

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Keep it up. My wife and I haven’t gotten it and I’m still shopping in an N95. I’ve seen an uptick in other masked persons lately.