dfox

11 ms·

121.
by dfox 2y ago
SDs and eMMC also usually have the same feature as the famous IBM “DeathStar” HDDs from the 00's: the thing gets completely hosed when it loses power when write is in progress. I do not have exact statistics but I believe that this is
122.
by dfox 2y ago
IKEA has consistent smart system that has the annoying feature that it works the wrong-way around for my use-case. The cheap IKEA switches can control IKEA peripherals only directly, you can't use them to control something outside of t
123.
by dfox 2y ago
IIRC when we wanted to move one of the pretty large IKEA dressers that had to be at least partially disassembled to fit through the door there was no non-destructive way to dismantle it. And that was not about trivial things like the back p
124.
by dfox 2y ago
That actually makes more sense than the usual opposite approach of using over-long encoding for NULs in the data.
125.
by dfox 2y ago
My favorite case of solving a software problem in hardware involves precision kick with steel-toed boot, which caused part of the machine to bend slightly such that the timing/position errors in software would not cause a jam.
126.
by dfox 2y ago
One thing is when you do that as an exploit, another thing is doing that intentionally in order to fix an obscure issue in production without down time and having to recompile the thing. At seven in the morning after a whole-night infrastru
127.
by dfox 2y ago
Loadable device drivers are somewhat modern invention. On many systems adding a device driver involved recompiling (or at least relinking) the kernel.
128.
by dfox 2y ago
You punch 80 columns worth of DEL. The card will jam the reader, but will get punched just fine.
129.
by dfox 2y ago
The message send syntax has one important nuance that you will be hard-pressed to somehow simulate with CPP: the selectors are actually interned so the message dispatch does not compare strings, but pointers. This difference has very meanin
130.
by dfox 2y ago
My two cents: monitoring RAM usage is completely useless, as whatever number you consider an “used/free RAM” is meaningless (and the ideal state is that all of the RAM is somehow “used” anyway). You should monitor for page faults and c
131.
by dfox 2y ago
I know only one access system that is built on Mifare and does not use UID, and that thing uses a file on the card as a bitfield of what doors it can open.
132.
by dfox 2y ago
The main point from that is that you should never do a system with stored value on a smart card. The vendors will show you various methods for that, but well it is 2024, just do that online (and the card is just an ID, which optionally can
133.
by dfox 2y ago
Non trivial amount of RFID access cards work the wrong way around, ie. the reader authenticates to the card.
134.
Codapi: Interactive Code Examples"(codapi.org)
2 points by dfox 2y ago|0 comments
135.
by dfox 2y ago
I suspect that the comment implies the absence of project manager on the Entropic side of the deal. As for the cost of the badge, sourcing even sub-$1 badge is still a project. And especially when your target audience is somewhat skilled at
136.
by dfox 2y ago
15+ years ago many people would tell you that you should do “from foo import bar” instead of “import foo” to save the overhead inherent in referencing “bar” as “foo.bar”. Well, as almost everything in Python is in the end an dict, the dict
137.
by dfox 2y ago
Technically an extension cable with USB-A jack is forbidden by the USB spec anyway.
138.
by dfox 2y ago
Typical keyboard is USB Low Speed device (which is why it has relatively thin flimsy captive cable). If you do not care about actually meeting the spec and are only concerned about the thing working reliably you can bit-bang that on essenti
139.
by dfox 2y ago
The effects of preprocessor in C are quite significant. Old DOS Turbo C had shown amount of lines compiled and the speed in the compilation progress window in the IDE. IIRC straight #include <stdio.h> #include <stdlib.h&g
140.
by dfox 2y ago
You still refer to logical decoding as part of recovery in the last section. The main point is that WAL by itself is designed only for data recovery and only contains information about what is going to be written where in terms of essential
141.
by dfox 2y ago
> Then, there’s a random byte like 0x25 or 0x07 followed by the column data – the rest of the columns are string types so they’re all stored in UTF-8. If you know what these inter-column bytes mean, leave a comment below! I can’t figure
142.
by dfox 2y ago
> This process of retrieving the expected database state from the WAL is called logical decoding and Postgres stores files related to this process in here. While logical decoding is about WAL, it is not related to the recovery process. L
143.
by dfox 2y ago
ASDF is one of the symptoms of what is wrong about CL. You have this thing that is not really sure whether it is image based or source based and has a bunch of global state while reading the source. Solution to that is ASDF, which is a ridi
144.
by dfox 2y ago
The common definition of “Aspect oriented programming” is more or less “just bolt whatever CLOS method combinators already can do onto another language”. That is powerful concept, but maybe somewhat orthogonal to macros, unless you want to
145.
by dfox 2y ago
The idea behind that is neat. And well, the conversion from the ladder diagram to PLC bytecode is intentionally so trivial that it can be done by hand if the ladder diagram is drawn in certain way (which is the way the first PLCs were progr
146.
by dfox 2y ago
Another thing is the ability to actually have a breakpoint in the program. There is a lot of distributed systems (especially embedded ones) where just stoping the program and inspecting the state will cause the rest of the system to enter s
147.
by dfox 2y ago
kvm_getprocs is in userspace library libkvm which abstracts away how that is done. And that library is primary meant for accessing /dev/kmem and crashdumps, with this functionality being bolted onto it (FreeBSD manapage even menti
148.
by dfox 2y ago
> So why did the stipple go away? I’m not terribly certain to be honest [...] I always assumed that the reason was that it was time when cheap (and low-quality) LCD displays with VGA-only inputs started to appear en-masse. And on most su
149.
by dfox 2y ago
It is not really about saving one oscillator, but about two things: - saving the drive circuitry for the flyback, which is usually combined with horizontal deflection amplifier. Also such a design probably simplifies the output filter for h
150.
by dfox 2y ago
Which I believe is the reason why people believe in some kind of deity. Believing of some kind of deity does not exactly answer the question of “why we are here?” but it can be trivially used to argue out this apparent paradox.

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