dfox

44 ms·

331.
by dfox 3y ago
That is completely different definition of HF. And if they use radio (lower latency than fiber, in theory and in right circumstances ), it is somewhere between SHF and EHF (C through V in the IEEE nomenclature), ie. what sane person would i
332.
by dfox 3y ago
Only insignificantly. Most of the radiation is filtered/diverted by the magnetosphere. The only really practical effect of the disturbance is making the already hard to predict sky-wave propagation of HF even more harder to predict and
333.
by dfox 3y ago
Quite recently on ACOUP appeared an button to switch the color scheme (the circle with flame emoji in the lower left corner). Somewhat ironically for me (who mostly reads it on iPhone) the button itself is somewhat distracting while I'
334.
by dfox 3y ago
Modern ADSL and VDSL version typically use DMT, which is more or less the same thing as OFDM. Interesting part of that in context of xDSL is that each of the subcarriers (typically QAM-64 modulated) can have different amount of actual paylo
335.
by dfox 3y ago
Apparently the Intel's marketing had forgotten that they already had a product called iAPX (standing for “Advanced Performance arCHitecture”) and it did not go exactly well :)
336.
by dfox 3y ago
I remember that in 1991 there was an article (IIRC paid PR by Siemens) how the checkout by RFID is the next big thing that will happen the following year. 20 years later it started to really pop up in the stores in the form of EPC Gen2 RFID
337.
by dfox 3y ago
This was common in Czech Republic, but the large stores switched back to weighting at the cashier checkout. I assume that the way how the consumer-facing scales are connected to the rest of the store's system has something to do with t
338.
by dfox 3y ago
scanf() is probably not the right approach to that, but still you can implement a parser for the common INI syntax in about a third of the code with fgets(), strchr()/str(c)spn and bunch of hand-rolled ad-hoc logic.
339.
by dfox 3y ago
The trick for “lets hand write a parser, it is simple” is in coming up with grammar that is either LL(1) or slight superset of that that can still be parsed by recursive descent with hand rolled deconflicting rules (prime example of that is
340.
by dfox 3y ago
ungetc() exists for exactly this application. But when you want more abstract input stream than FILE* you have to reimplement that yourself on higher layer. Ironically even libc implementation needs an more generic abstraction to implement
341.
by dfox 3y ago
This has nothing to do with Linux, but with quality of firmware in embedded controllers combined with laptops with internal non-removeable battery.
342.
by dfox 3y ago
After my first car was stolen I went out to design and build an immobilizer system based on these PIC16F84 AlphaCard “smartcards”. Along the way I realized that what matters most is that it is obvious that there is something obscure like th
343.
by dfox 3y ago
One of my exploratory projects while I still though that academics career made sense involved replacing smalltalk's stack based bytecode with incrementally transformed S-expression trees. Naturally the first thing I went out to do was
344.
by dfox 3y ago
Somewhat famously the i686 designers boasted about the amount of automation used in the design (and the DEC's marketing department got a lot of traction from presenting Alpha as “hand designed”), so it makes sense to assume that earlie
345.
by dfox 3y ago
> Multi-character constants are historical baggage. It is more that it is an implementation detail of some compilers that was then (ab)used by certain platforms.
346.
by dfox 3y ago
If you want version control you need a format, that is amendable to version control. So, some uncompressed text markup. Interesting observation over the last few weeks of playing with OpenDocument is that the revision control feature works
347.
by dfox 3y ago
MIDI is similar to RS-232 only if you conflate RS-232 (which specifies voltage levels and physical connector) with asynchronous start-stop serial, while that is the most common application for RS-232, it can be carried over a lot of physica
348.
by dfox 3y ago
Except on Windows for Workgroups and Windows 9x/ME the fact that you can dismiss the login dialog is intentional feature, so bypassing it through help is just a more convoluted way of doing something that should be possible. It is feat
349.
by dfox 3y ago
What is somewhat more concerning is that depending on the particular Android version and OEM customizations there are various way how to get into this browser or even complete Android Setting screen from the on boarding flow. Most FRP-bypa
350.
by dfox 3y ago
There are different modes in which 6500 can operate. The original 15Mpps mode (30Mpps is architecturally the same thing at higher clock speed) involves the line card arbitrating for a shared parallel bus on the backplane, transfering releva
351.
by dfox 3y ago
Cisco specifies Sup720 as being capable of “up to 400Mpps*” routed IPv4 with the footnote implying that this is in dCEF mode. With dCEF, each linecard has its own forwarding logic, so the lookup time deadline has to be multiplied by number
352.
by dfox 3y ago
6500/7600 is weird beast where the same HW architecture (and well 4 generations of it that are to some extent compatible although internally very different) are used as both high port density ethernet switch (6500) and as an router (76
353.
by dfox 3y ago
Motif/libxm is very similar to that. With two important exceptions: the user code does not use type-checking macros and “stringly-typed” API for set a property to something is more or less a part of the overall ecosystem (well, Xm is j
354.
by dfox 3y ago
As a guy who had installed vanilla Debian on a bunch of QNAP and Synology NAS boxes I don't understand what exactly is the reason why anyone would want ZFS. The thing is completely unintuitive when something breaks and also there are s
355.
by dfox 3y ago
Indeed, what the various “reactive” frameworks do is in the end the idea behind MVC, although as they are web-based the implementation is ridiculously complex and the abstraction is very leaky.
356.
by dfox 3y ago
Throw a ridiculous amount of RAM at it is more correct assessment. NVMe reads are still an “I/O” and that is slow. And for at least 10 years buying enough RAM to have all off the interesting parts of OLTP psql database either in shared
357.
by dfox 3y ago
All postgres processes run under the same system user and all the access checking happens completely in userspace.
358.
by dfox 3y ago
Well, hour and half per week is the amount of downtime that you need for modestly sized database (units of TB) accessed by legacy clients that have ridiculously long running transactions that interfere with autovacuum.
359.
by dfox 3y ago
Running the whole DBMS as a bunch of threads in single process changes how fast is the recovery from some kind of temporary inconsistency. In the ideal world, this should not happen, but in reality it does and you do not want to bring the w
360.
by dfox 3y ago
Schnorr-like (including DSA and ECDSA) signature schemes use a parameter "k" that has to be uniformly random, secret and non repeating for the security of the system, calling that a "nonce" is slightly weird. Edit: the i

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