I doubt anybody uses a Klystron for heating applications. It's always a maggie, whether it's in your home microwave or large industrial units.
Also, another niche that tubes occupy is high voltage + high current applications (solid state lets you pick any one, not both). For example, I use a 7322 hydrogen thyratron to switch about 500 amps at 10 kV (modulator for a Klystron), and I'm nowhere near it's 5000 A, 25 kV limit. The few SCR stacks that come close need lots of cooling, have poor rep rates and are expensive.
but you CAN hear when something in the environment rectifies it and low pass filters the signal envelope
You forgot to mention "amplifies". Without that, the effect is quite imperceptible.
I work at a weather radar facility, and shortly after I joined, I used to complain to my co-workers that I could "hear the radar PRF" (approx 1 kHz). They laughed and said I must be dreaming. It turned out that one of them is a volunteer at the local fire department, and had his emergency radio tuned in and running all the time (squelched). When the radar antenna swung by the office building, the radio would get just enough power to break out of the squelch, and buzz at the 1 kHz pulse rate of the radar. This is what I heard, from down the hall. For reference, this is an S-band system (2.7 GHz), peak power ~1 MW, with a 46 dBi antenna. ERPs are far higher than any WiFi system or cell phone.
Mod parent up. I find it funny, too, that so many struggle so hard to get "real time" interrupt handling when very simple application of FPGAs would solve their problems neatly and with a lot less work. This doesn't even mean you need to go the Microblaze/NIOS route, use an ARM/PPC/whatever, couple it to the FPGA with some simple bus (SPI?) for control functions, and you're all set.
Yes sir, I'm fully aware that a synchronous design won't run without a clock. All I said was that you will get decent results even if you don't include timing constraints in your design for 80% of simple designs.
Synthesis, in particular, doesn't need to know about clock speed. You only need timing constraints for place-and-route (and translate/map if you enable timing driven map). Then again, there's all this fancy stuff from Synopsis, but the OP is a beginner, and very unlikely to be using the fancy tools.
I fully agree about VHDL making more explicit the fact that you're designing hardware, not writing code that gets executed sequentially.
I'd think that it would be best for beginners to not bother with timing tools while they're still beginners. It tends to develop the tendency to "over optimize" right at the start. For the most part, simple (ie, low-speed) designs will work well even without timing constraints.
Initially, I was quite surprised he could squeeze enough stuff to build a computer capable of running a BASIC interpreter on a single Augat board, given his claim of only using 7400 logic.
Scroll down to the Board Layout on his blog, you'll find that many of the supposed "7400" logic chips are actually 20V8 and 22V10 PALs. Programmable logic heresy, I tell you!
The actual 7400 logic chips I found so far are: 74LS74 (Flip flops), 74LS139 (dual 1:4 decoder), 74LS161 (dual 4-bit counter), 74LS163 (dual 4-bit counter), 74LS181 (ALU), 74LS244 (Bus transceiver), 74LS377 (octal D flip flop).
Given that mix, I would say this falls somewhere in the MicroVAX era, which had a similar mix of low-density PALs and 7400 logic. My colleague at work used to make stuff on similar boards. Some examples include a color display driver (for a VAX) and an antenna positioner (again, for a VAX). The display driver has long been replaced by Linux boxes, but the antenna positioner (and VAX) still lives on.
Steve, if you're reading this, we still have lots of Augat boards kicking around, along with lots of boxes of 7400 logic (sorry, no 22V10s!)
I don't think China would want to cease aid to North Korea, because this would open up a flood of refugees. Millions of refugees crossing the border, particularly in the current economic slump, would be disastrous. Also, North Korean nuclear weapons technology was only indirectly provided by China, it came from AQ Khan, in Pakistan.
For me, this was with DJGPP and CWSDPMI which gave me protected mode support under DOS. I wish I had switched over to Linux back then, it would have saved so much pointless junk like that...
Not sure how one would do this and still allow more than one program to touch the sound hardware.
One way would be to have sound hardware with a hardware mixer. Example: emu10k1. Dig deeper and you find the emu10k1 resamples everything to 48 kHz before sending it to a DAC.
Next way: ALSA+dmix. Same deal, everything is resampled to a fixed rate.
Pulseaudio: you've already covered that.
The only way I can think of to play back audio from more than one program with multiple sample rates is to have multiple DACs, each with their own sample rates, and mix the analog signals.
Slashdot Mirror
Also, it would only work in the daytime.
You just need to break the problem down to individual parts...
Fry: Did everything just taste purple for a second?
You, me, and the guy who cried after being able to read again (from TFA)
Forrest's statement of "she tastes like cigarettes" takes on a whole new meaning!
I doubt anybody uses a Klystron for heating applications. It's always a maggie, whether it's in your home microwave or large industrial units. Also, another niche that tubes occupy is high voltage + high current applications (solid state lets you pick any one, not both). For example, I use a 7322 hydrogen thyratron to switch about 500 amps at 10 kV (modulator for a Klystron), and I'm nowhere near it's 5000 A, 25 kV limit. The few SCR stacks that come close need lots of cooling, have poor rep rates and are expensive.
Anything that can store data never goes out. till it's been through the shredder.
Except the camera that took the video...
"Enough is enough! I have had it with these motherfucking lasers on this motherfucking plane!"
That'll be great, until the Laughing Man decides to hack in to those glasses...
Augmented reality - Microsoft style. Scroll down to item #13.
but you CAN hear when something in the environment rectifies it and low pass filters the signal envelope
You forgot to mention "amplifies". Without that, the effect is quite imperceptible.
I work at a weather radar facility, and shortly after I joined, I used to complain to my co-workers that I could "hear the radar PRF" (approx 1 kHz). They laughed and said I must be dreaming. It turned out that one of them is a volunteer at the local fire department, and had his emergency radio tuned in and running all the time (squelched). When the radar antenna swung by the office building, the radio would get just enough power to break out of the squelch, and buzz at the 1 kHz pulse rate of the radar. This is what I heard, from down the hall. For reference, this is an S-band system (2.7 GHz), peak power ~1 MW, with a 46 dBi antenna. ERPs are far higher than any WiFi system or cell phone.
Will one of them be Iraq?
Funny, that hasn't worked for me so far (five years in the US and counting)
Antique-ing?
Mod parent up. I find it funny, too, that so many struggle so hard to get "real time" interrupt handling when very simple application of FPGAs would solve their problems neatly and with a lot less work. This doesn't even mean you need to go the Microblaze/NIOS route, use an ARM/PPC/whatever, couple it to the FPGA with some simple bus (SPI?) for control functions, and you're all set.
*sigh* OK, you win the internetz. I guess I've been doing it wrong all these years.
Yes sir, I'm fully aware that a synchronous design won't run without a clock. All I said was that you will get decent results even if you don't include timing constraints in your design for 80% of simple designs.
Synthesis, in particular, doesn't need to know about clock speed. You only need timing constraints for place-and-route (and translate/map if you enable timing driven map). Then again, there's all this fancy stuff from Synopsis, but the OP is a beginner, and very unlikely to be using the fancy tools.
I fully agree about VHDL making more explicit the fact that you're designing hardware, not writing code that gets executed sequentially.
I'd think that it would be best for beginners to not bother with timing tools while they're still beginners. It tends to develop the tendency to "over optimize" right at the start. For the most part, simple (ie, low-speed) designs will work well even without timing constraints.
Initially, I was quite surprised he could squeeze enough stuff to build a computer capable of running a BASIC interpreter on a single Augat board, given his claim of only using 7400 logic.
Scroll down to the Board Layout on his blog, you'll find that many of the supposed "7400" logic chips are actually 20V8 and 22V10 PALs. Programmable logic heresy, I tell you!
The actual 7400 logic chips I found so far are: 74LS74 (Flip flops), 74LS139 (dual 1:4 decoder), 74LS161 (dual 4-bit counter), 74LS163 (dual 4-bit counter), 74LS181 (ALU), 74LS244 (Bus transceiver), 74LS377 (octal D flip flop).
Given that mix, I would say this falls somewhere in the MicroVAX era, which had a similar mix of low-density PALs and 7400 logic. My colleague at work used to make stuff on similar boards. Some examples include a color display driver (for a VAX) and an antenna positioner (again, for a VAX). The display driver has long been replaced by Linux boxes, but the antenna positioner (and VAX) still lives on.
Steve, if you're reading this, we still have lots of Augat boards kicking around, along with lots of boxes of 7400 logic (sorry, no 22V10s!)
Only if they are scanning sharks...
I don't think China would want to cease aid to North Korea, because this would open up a flood of refugees. Millions of refugees crossing the border, particularly in the current economic slump, would be disastrous. Also, North Korean nuclear weapons technology was only indirectly provided by China, it came from AQ Khan, in Pakistan.
...maybe if it said "eight-head" setup?
And I'll wager, um, a 555 in a DIP or SOIC that more than half of Slashdot doesn't know what a TO can is :)
For me, this was with DJGPP and CWSDPMI which gave me protected mode support under DOS. I wish I had switched over to Linux back then, it would have saved so much pointless junk like that...
Not sure how one would do this and still allow more than one program to touch the sound hardware.
One way would be to have sound hardware with a hardware mixer. Example: emu10k1. Dig deeper and you find the emu10k1 resamples everything to 48 kHz before sending it to a DAC.
Next way: ALSA+dmix. Same deal, everything is resampled to a fixed rate.
Pulseaudio: you've already covered that.
The only way I can think of to play back audio from more than one program with multiple sample rates is to have multiple DACs, each with their own sample rates, and mix the analog signals.