I heard about the same story about the HP3000. Some manager asked an engineer if he wanted any improvements, and he said "eliminate the divide instruction", so they did. It was also a microcoded CISC architecture.
-- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
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Of course you can. If the temperature measuring device is part of what you are measuring it no longer would be a thing that is changing the temperatu re. It's part of the solution rather than part of the problem.
If I connect a temperature measurement device to a heat sink to measure it' s temperature. I don't care is that temperature is slightly different from what it would have been without the thermometer. The thermometer is now p art of what I am measuring.
-- Rick C. ++- Get 1,000 miles of free Supercharging ++- Tesla referral code - https://ts.la/richard11209
there's several, eg: op-code ED,78 "out(c),a" writes the contets of A to the port address in BC
maybe you're thinking 8080
-- Jasen.
On checking, it looks like you are right.
Either my memory is faulty after half a lifetime, or that compiler only targeted the 8080.
On a sunny day (Sat, 13 Jun 2020 08:50:53 +0100) it happened Tom Gardner wrote in :
Most C compilers have an option for inline asm?
The early PICs had segmented memory, I use the 18F14K22 the 18F series has a much nicer architecture and instruction set.
But what also counts is the UNDERSTANDING of the BASICS these days programmers just link in library after library... For video I started in the tubes age, worked with tubes complete studio with .. tubes.. then logic with transistors and yet we had all the special effects. In 1967 when color came here where I lived with PAL things became solid state, no computers anywhere, hardisks? Sure:
Sure, there are even satellites in space running Linux. Also the large (and tested) open source software base probably reduces bugs.
OTOH if I do 'ps avx' on my Linux laptop there is so much running that I really do not 100% know what it does, so have to google for it... The chances of having your spacecraft hacked and taken over by or used for crypto mining, or the astronuts getting a screen message 'pay now' are not zero.
The more megabytes of interlinked code, on ever smaller silicon structures, the more chances a cosmic ray will bring down the whole system.
Seen a nice documentary about the Voyager spacecraft, not much more on board memory than 32 kB, still transmitting.
Silly media show astronuts in zero gravity brewing their own beer is a disgrace. US could have been playing golf on mars..
Soon as the Chinese restaurants will be open on that planet...
The question that comes up is: Will the next world war bring us all back into the stone age, or will competition and evolution bring us to other planets, like the V1 V2 and Von Braun eventually took us to the moon?
On a sunny day (Sat, 13 Jun 2020 09:53:58 +0100) it happened Michael Kellett wrote in :
I have used i2c from the beginning, even used it externally to drive displays in an office building via hundreds of meters of cable. I _never_ use onchip hardware I2C, always my own libraries. Make sure you got bus init right on power up. Much micro on chip hardware i2c is buggy and the next silly-con errata then claims a fix, and the next .. So far never a problem, no power cycling used ever.
We haven't either, except occasionally during debug. It's more of a belt-and-suspenders thing, because some of our stuff is safety-critical and runs for long periods (think cotton spark detectors for textile mills).
The I2C stuff isn't the safety-critical part, of course--it does jobs like T/H data collection for dew point calculations, to see if the window is liable to fog up, and setting offset voltages via DAC. We also use small I2C EEPROMs for holding parameters and logging anomalies.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
"Very deep. You should send that in to the Reader's Digest--they've got a page for people like you." --Arthur Dent, in THHGTTG.
;)
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
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Oh, I thought he meant that there is always some self heating of the device.
GH (who should reread HHGTTG)
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tEven if there is, in most electronic applications it is now part of the thi ng being measured and so has no impact on the measurement. The self heatin g is just another effect to be taken into account like the thermal impedanc e between the desired location of the measurement and the actual location. Any "self-heating" from the sensor that actually changes the temperature o f the thing being measured is now part of the design so not a "changed" mea surement by definition.
-- Rick C. +++ Get 1,000 miles of free Supercharging +++ Tesla referral code - https://ts.la/richard11209
There is a fundamental physical principle that you can't measure something without affecting it. However, you can measure a great many things without having any practical or noticeable affect on them. Yes, any temperature measuring device will be subject to self-heating but it is usually completely irrelevant. Unless you are doing cryogenic stuff or something with extreme precision, the self-heating effects will be drowned out by calibration errors, analogue noise, thermal resistances, ADC errors, etc.
It should be re-read on a regular basis!
Preferably listen to the original: the radio series. In a dark room. I can do that with an ex-leopard on top of a filing cabinet, but that's optional
The radio pictures, aural and otherwise, are much /much/ better than any of the other soulless formats.
(One format exception: Ken Campbell's stage production at the Rainbow, which accurately captured the spirit of the original Zaphod Beeblebrox. Not a crap prosthetic head, but two people in one jumpsuit. I expect they preferred playing that to playing a pantomime donkey)
I'm not sure I agree. Douglas Adams was a great fan of different media
- as long as you realised the same story was a little different in different formats, and took advantage of that. He thoroughly approved of the radio series, the books, and the BBC television series - each a little different, but each good in their own ways. And he had always wanted to make film version too, just not anything remotely like the horror that was produced the moment he was no longer able to keep it back.
A TV show was made with the Dirk Gently character and it was good. It was absolutely nothing like the book, but good in it's own right. So I was not offended that they ripped off the title.
"Dirk Gently..." was a good book, but clearly one of his earlier works with less polished humor and effects. I recently read xkcd from number 1 and saw a similar progression both in the art and the humor. Both artists are very talented.
-- Rick C. ---- Get 1,000 miles of free Supercharging ---- Tesla referral code - https://ts.la/richard11209
I don't disagree, but I'll not change my statement.
The 1981 TV series was a curate's egg.
Zaphod Beeblebrox' second head was risible, Marvin was OK but not as good as the picture in my head.
The graphics were excellent, especially for the time. Unfortunately they were /so/ good that I found myself concentrating on the graphics to the exclusion of Peter Jones' voice of the HHGttG. Not so good.
Cheers
Phil Hobbs
Well, kinda. You need a part of the thermometry apparatus to be in equilibrium with the temperature of the system, so it has to be inserted into the apparatus (and presumably has its own heat capacity). That implies that some heat flows into/out of the thermometer.
But, you can probe (for instance) a phosphor to see its time-decay, and that only intrudes a few input photons, not a lot of energy involved. Or, you could reflect a laser beam and look at Doppler broadening (if reflection is efficient, that's nearly zero energy input). The probe doesn't need to do work on the system being measured.
lection
The whole assumption is that the thermometer is not part of the thing being measured. Does an outdoor thermometer disturb the day's temperature? No, because it is part of the thing being measured. To read it only requires that the light which is also part of the thing being measured falls on your retina.
No disruption.
Once the thermometer is on the PWB if there is any impact on the chip tempe rature it is irrelevant because the thing being measured is still the thing being measured even with the thermometer on it.
It's a bit like shipping software with debug turned on. Whatever impacts t hat setting has on the software is now part of the system being debugged.
-- Rick C. ---+ Get 1,000 miles of free Supercharging ---+ Tesla referral code - https://ts.la/richard11209
I'm sure he did. Thing is, most all temperature sensors measure their _own_ temperature, and we use that as a proxy for the temperature we actually care about. In situations where the self-heating of a thermistor is a worry, there are many, many ways of compensating for that, e.g. short duty cycles; on/off chopping; measuring the power-up transient on the thermistor; and on and on.
In my world, the self-heating can almost always be ignored as long as it's constant--it's the temperature variation in peformance of lasers and detectors that we're mostly fussed about. A nice stable quarter degree of self-heating is a nit compared with the rest of the system variations.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
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