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Comment The good, the bad, and the ugly... (Score 3, Interesting) 467

Maybe I mostly remember the slings and arrows -- these so-called BASIC program listings that were about eight lines of actual readable (and thus re-writeable) BASIC code and the rest of the page or pages being DATA statements with numbers. Then the PCs came, and we could, if sufficiently masochistic, type in similar listings to use with DEBUG.EXE. Later, as software grew larger, there soon came the need of faffing about with config.sys and autoexec.bat so that available memory was maximized. In the late 1980s onwards, there were the expanded memory nonsense too and more and more options and things in config.sys. There there would be jumper settings so DMA channels, port-addresses and interrupt lines on the various plug-in cards in the PCs. This continued well into the 1990s, then that got replaced by something called Plug-and-play which maybe, maybe not, did work, thus everyone called it "Plug-and-pray". And all on the original 640K plus whatever High memory had been put into place. I do not miss any of all this. TFS mentions the dreariness of business computing. they are absolutely right!

But I might not be typical -- I started with learning FORTRAN, then after that BASIC seemed primitive (no functions? and thus no data hiding? i have to make sure I don't re-use any of the variable-names anywhere else? and only one letter? at least FORTRAN allowed me to use six! bah) but the PC-compatible had Turbo Pascal, and there was also the assembler and later, Turbo C, so that became a nice set-up, with direct control of the pins on the parallell and serial ports, and even some DIY card with A-D converters! Yay!

Then there were the wonderful Unix systems, HP-UX and AIX back around the mid-1980s, where you could actually do more than one thing at a time without the machine crashing. And even if your program decided to hang, or accessed some memory out of bounds, it would say "bus error" or "segmentation fault" and stop, but the rest of the system, including other programs, would continue happily along as if nothing had happened. These even had networking so we could have programs on one machine talk with programs on another machine.

Of course this didn't last. Those Unix systems were way too expensive. Instead, Windows NT happened, and a form of multitasking and even eventually a useful networking system (TCP/IP is useful, all the other weird and wonderful variants turned out not to be so) and the access to the parallell port vanished, while the support for the serial ports became increasingly wobbly. ISA, EISA, Micro Channel, and MS-DOS became dinosaurs soon after; parallell and serial ports followed on as being branded "legacy". And like the dinosaurs, some of their descendants are still around now: RS-232 serial ports never really went away completely. USB came, but turned out to not be as hacker-friendly as those serial ports -- there is a reason everyone today runs (RS-232 style) serial via USB using a pl2303 or FTDI or similar chip to talk and listen to the UART in their SBC or microcontroller board.

There was a sort of dark age, of PCs running klunky MS-DOS or slightly less klunky Windows, until the late half of the 1990s, when Linux distros became easily available, and so good that they actually worked right on some reasonable random PC hardware that would be available, and all the good old Unix ways of doing things finally became economically feasible, intially on PCs, many of them second-hand. Around the middle of the 2000s the first single-board computers started showing up, and some of these are now becoming as understandable and documented as those old 8088 PCs with their MS-DOS once were.

To some extent we are in a golden age right now.

Comment Re:Has the Internet Killed Curly Quotes? (Score 1) 207

The most common way of highlighting special items such as filenames, functions, variables, command-line invocations and suchlike in documentary text is to put them in an alternate font, sometimes italics or bold. In code, quote-characters mark the beginning and end of a string to be displayed, and there are escape-conventions for including the same quote characters within the string as part of it. As far as the compiler looking at that is concerned only the non-escaped quote characters at the ends are taken as meaning begin and end string.

If there is something more of a nontechnical work, say, a novel where protagonists A and B are discussing their concerns raised by the absence of a file and the spelling of its name, it might be useful to show what we could call human and non-human audience quote characters. But here the audience is human, and we are known to be pretty good at understanding even when faced with moderately severe syntax errors.

Consider also the convention in print that long quotations that go over several paragraphs have open quote characters at the beginning of each paragraph, but only one closing quote character at the end. Useful for human readers, but makes for many complications to a system that expects quote-characters to appear in pairs separating what is inside and outside.

Comment Re:So annoying (Score 1) 207

Indeed, they also would confuse us using those fancy text-figure numerals that makes lowercase o and zero indistinguishable, just so that even if you can read and ignore the curly-ness of the quotes, you won't be able to get this other distinction right when it isn't obvious from context. Same for uppercase I and lowercase l in most sans-serif fonts, but copy-and-paste might be able to handle these. It it wasn't for these stupid quotes of course...

It all comes from having overloaded some characters: the ASCII 0x22 character has been pressed into service for denoting inches, seconds of arc, beginning a quote, ending a quote, ditto mark. Similarly, there is the characters for minus, em-dash, en-dash, hyphen all being represented by ASCII 0x2d. So how do we know which ones we will want to use? I can think of writing prose where the storyline might have to include pieces of programming code, and thus will want to have all these different ones there at the same time.

Comment Re:Not subsidies (Score 1) 16

Teslas and other electrical cars do not have VAT charged on the sale price, and once on the road it can be driven for free on all the toll roads and toll-enclosed city centers. Annual registration charge is also the minimum rate otherwise applicable to veteran cars, older than 30 years, and they are allowed in most of the bus and taxi lanes. The term subsidy has been used for this, maybe it should be called tax relief, or incentives, or something else. However, whether the government pays extra for something or just refrains from charging taxes on something doesn't make much of a difference in the end: it does make these cars much more popular than they would have been otherwise.

Now as for autonomous cars in this place where the winter is an inferno in white with snow or an inferno in black with the grime and mud produced by salt and studded tires grinding up the pavement ending up all over the cars and the road; snow or mud covering road markings such as the center, lane divider, and edge lines (provided there are any there at all) -- then add the unique tendency of Oslo pedestrians to wander into the street in front of anything that moves (cars, buses, streetcars, bicyclists) never mind trafic lights... and the large population of moose and deer in the woodlands all over the place which isn't exactly known for their good traffic discipline either, and it is going to be really interesting to see how this experiment turns out!

Comment Whatever was wrong with local solar time? (Score 3, Interesting) 598

Changing everyone to use UTC all the time in order to obviate the problems with Daylight Saving Time is offering a cure rather worse than the disease. Nothing is all that wrong with the system of timezones, defined so 12 Noon is more or less in the middle of the day for everyone. By itself and for certain technical purposes UTC is a good choice, in the same way that base-16 number encoding is, but for everyday civil use it doesn't do the job well. Local time and base-10 works much better there.

If the Daylight Saving is the problem then the solution is to get rid of that then? Stay on local solar time as the existing timezone stipulates, and do not turn the clocks one hour back and forth every few months. The easiest solution is the negative one, in that it means not doing the stupid thing anymore.

Comment Re:What if he was using metric units? (Score 1) 512

Well since he is Italian, and was on his way to Canada, and if he were doing applied engineering math he might have been using metric units.

However, as his field of learning is economy, the most likely specific units that he might have been using would have been dollars ... which if not exactly metric, at least have the familiar base-10 divisions. But as he was working on some differential equations at the time, the use of specific units or even much in the ways of numbers would not be likely.

Comment Re:legalism is a crap philosophy. (Score 2) 582

25 MPH (or 40 km/h) on a road of the quality seen in the video will usually feel like it is too slow, and it is not surprising that there are many that exceed this limit.

I notice that most arterial roads around here have the equivalent of 30 MPH (50 km/h) though reduced to 40 km/h or 25 MPH past schools. Where there also is at least one speed bump or raised pedestrian crossing (basically a speed bump with the crosswalk on top). Non-arterial roads have 30 km/h (which would correspond to 20 MPH), and there are always speed bumps.

Comment Re:Needless limiting of options (Score 1) 170

Where not only the so-called TIPs, (by which is meant a certain series of reasonably popular power transistors in TO220 packages, designed by Texas Instruments) but also other devices such as 2N2222, LM386, and "bipolar transistors" and so on, are no longer to be used. Just because they might not be the best choice for switching loads controlled by an Arduino or similar.

So, I am not an EE, but it seems like what he's actually saying is that the MOSFET takes an order of magnitude less turn-on current and that it wasts an order of magnitude less power as heat. Is that true? And if so, why would you not want to save power? Are your driver transistors doubling as a heater?

A lot of the energy budget depends on the circumstances. When running on batteries, power draw is much more of a concern than when running on mains power. Similar with heating -- it may or may not be anything that needs to be attended to. Now having said that, there are several good reasons to use the MOSFET instead of the bipolar transistor, but they are not so overwhelmingly good that it makes sense to discard all kinds of bipolar transistors just because ot that.

The turn-on current for the MOSFET comes from charging the capacitor formed by the gate -- the instantaneous current is C dV/dt, in other words, the faster the transistor is asked to turn on, the larger, though briefer, will the current pulse required be. Once the transistor is turned on it doesn't require any current to stay on. There will however be another similar current spike, in the opposite direction, when the transistor is to be turned off and the gate capacitor is discharged. When the load is something like a motor, these time requirements won't be all that strict, so a controller is quite likely to be capable of driving the transistor. Now, without the necessary additional protective passive components (diode across the motor, maybe also a resistor and capacitor "snubber" circuit there as well; further diodes and resistors and capacitors around the MOSFET that serve to "eat" the energy coming from the motor being turned off) -- there is a nonzero risk that the load will turn on and stay on, having fried the MOSFET and maybe also the output circuitry of the microcontroller or Arduino...

In contrast, the bipolar transistor will require a steady base current for as long as the load is to stay powered, and they are more robust, less sensitive to surges and other influence of the load, and this does make it easier to make the circuit reliable, easier to make it work and easier to make it keep on working properly, The TIP120 and many of its relatives, being Darlington pairs, do have a fairly large current gain, so the required drive current is likely to be small enough for the microcontroller IO line to drive. But they have a voltage drop, and corresponding power loss, and are thus less optimal for driving motors. Which may or may not be a problem-- it will all depend on the actual application.

Thus, using a MOSFET for a switch has its advantages and its pitfalls like everything else -- and I don't have any objections to Tom Jennings recommending MOSFETs over bipolars for turning things on or off. What I do object to is the wholesale discarding of all bipolar transistors as if turning things on and off with the MOSFETs were the be-all and end-all of all electronics -- as we well know that is not so.

Comment Needless limiting of options (Score 5, Insightful) 170

Where to begin?

Should one even bother to do anything about advice from someone who goes on about enhancement MOSFETs while everything else is rubbish, and then present the circuit symbols for Junction FETs as examples? Makes one wonder what else is inaccurate there.

The actual advice of throwing out anything designed in the past century is at

Where not only the so-called TIPs, (by which is meant a certain series of reasonably popular power transistors in TO220 packages, designed by Texas Instruments) but also other devices such as 2N2222, LM386, and "bipolar transistors" and so on, are no longer to be used. Just because they might not be the best choice for switching loads controlled by an Arduino or similar.

This makes for a needless limiting of options -- If all one ever does is to turn things on or off from some microcontroller maybe, but with whatever designs I make I find that to be a small fraction of what is happening. The rest are things like multi-frequency linear or RF where all kinds of semiconductor devices might be applicable. Even vacuum tubes in some cases.

And then looking around the site and discovering the author is in his own words, "reasonably obsessed with the early history of electronic (not necessarily digital) computing" --- and then he advocates discarding what amounts to the elements of the analog electronic computers? This does not ring true.

Comment Re:Sticking with a 1982 design (Score 1) 698

From what I remember, the numerical keypads with 789 on the top row were inherited from ancient calculating machines, not entirely unlike the QWERTY ordering of the keyboard -- it was the way it was laid out and as it wasn't broke no-one ever bothered to fix it. There were some mechanical reasons for this originally, then it carried over to electronic calculator keyboards and then their descendants, the computers.

The phones keypad pedigree is different: from various circular dials that opened and closed a switch a number of times corresponding to the number the user wanted to dial, the keypads that replaced the dials got the numbers in a natural top-to-bottom ascending order, usually with keys organized in a 3 wide 4 tall matrix.

Comment Re:yes please: (Score 1) 698

I use the keypad while paying bills. There are account numbers, the amounts themselves, then these other long identifier strings of numbers that makes it certain that the mony ends up where it is supposed to go. Much easier than using the top row.

As for caps lock -- since I use vi a lot, the accidental turning on of this makes a lot of confusion since the various letter commands are different between upper and lower case: j moves down, J joins the line and the following then u is undo but U is undo to original text of the line. Then :e! starts over for another try...

Changing it to ctrl isn't great either, I'd type away at some website like this, then hit ^A and a couple letters later it is all: Where TF is all my text gone! Damn...

Thus, most of the keyboards here have the key removed so as to avoid the above kinds of hassles.

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