300MHz is for yesteryear, today most engineers need at least 1GHz to get by in digital design.
What I always find annoying about this is that once I am above 300 MHz or so where probing is easy, I am more interested in signal integrity issues where a high bandwidth low sampling rate sampling oscilloscope would be more cost effective than a lower bandwidth higher sampling rate real time oscilloscope yet the former are nonexistent and the later are too expensive.
Even professionally, I've found a 2-channel 50 MHz analog scope to be a godsend in some cases; of course, I like my 4-channel 1GHz digital scope more:)
I find that this is usually a probe limitation rather than an oscilloscope limitation.
The most useful oscilloscopes I use are either 100 MHz and below where passive x10 probes are still acceptable for general purpose use or 200 to 500 MHz depending on oscilloscope input capacitance where the fastest x10 passive probes still work probing 25 ohm circuits but in the later case, ground lead length becomes an issue.
My fastest oscilloscope for the later case is only 300 MHz.
The "1960s analog plug-in-based mainframe that is a '70s hacker dream scope" that he mentions might be pretty good. I have a few 400+ MHz similar oscilloscopes which have capabilities not readily duplicated in modern equipment.
One of my favorite tricks when working on digital/analog hybrid circuits is to use the microprocessor to set an output pin, then use the signal to trigger a scope
I still do this for debugging software. An oscilloscope is great for getting an idea of the minimum, maximum, and distribution of interrupt latency and subroutine run time.
This is going to depend a lot on what kind of electronics you do. Since I do mixed-signal work, oscilloscopes are invaluable. I have 10+ but only a couple will fit on my workbench at a time although I have carts for them. They are all old enough to drink.
1. Weller Magnastat temperature controlled soldering iron. I have a vacuum desoldering head for it also. 2. 2 or more function generators. 3. 2 or more pulse generators and leveled sine wave oscillators. 4. 2 dual output tracking power supplies plus some other power supplies. 5. 3 bench multimeters and a pair of 4 and 5 digit handheld multimeters. These can measure temperature as well. 6. 3+ universal timer counters. Two of my analog oscilloscopes include this capability. 7. 2 combination analog and digital 2 channel 100 MHz oscilloscopes. Of the oscilloscopes I have, I use these the most. I actually have 4 like this but tend to use them in pairs. 8. 2 channel 300 MHz DSO. This has word recognition triggering so it is my current substitute for a logic analyzer. 9. Small 100 MHz bench analog oscilloscope which usually has a curve tracer installed. 10. Big 400 or 500 MHz bench oscilloscope that may be analog, analog storage, or digital depending on what I am doing. 4 channel dual sweep or even dual delayed sweep capability means these can effectively be two oscilloscopes in one and they can do things I have not seen any modern oscilloscope do. 11. If necessary I, break out the 1 to 14 GHz analog sampling oscilloscope plug-ins. This makes great eye diagrams although my analog oscilloscopes can do that up to 400 MHz. 12. A big two output isolation transformer for working with off-line switching power supplies.
The one thing I am missing which I would like is a fast waveform acquisition digital storage oscilloscope that can make histogram waveform measurements although I can do that with any of my analog oscilloscopes pretty well if dealing with standard deviations. This is one area where an old analog oscilloscope can beat out an inexpensive digital storage oscilloscope.
Those in the know will recognize that I have a lot of old Tektronix equipment and some of the model numbers. I wish their new products were as good.
They are serial in respect to how the data has to be reassembled to compensate bit skew at the receiver. With a parallel bus the bit skew is less than the bit timing so all bits can be latched simultaneously from the same clock. With a serial bus like HT, QPI, the wider versions of PCIe, and more recent DRAM buses, the bit skew is greater than the bit timing so each lane has to have its own phased locked clock signal and assembling all of the bits together happens at a later stage. In practice either a clock embedded in each data line is used or a synchronous clock line for each small group of data lines but in the later case skew compensation is often still needed.
A number of them were shocked to learn how powerful NSA has grown.
Captain Renault: I'm shocked, shocked to find that gambling is going on in here! [a croupier hands Renault a pile of money] Croupier: Your winnings, sir. Captain Renault: [sotto voce] Oh, thank you very much.
In my opinion batteries sucks as energy storage for heavy loads like cars. Using capacitor banks to manage start/stop in city traffic and uphill/downhill is another thing.
Once you have enough of a battery to give you the range you want, then the power density is not a problem. The only capacitors you need are for high frequency decoupling and they only need to be selected based on ripple current and design lifetime.
1. Need to add in the cost of the electricity. 2. The battery is not going to deliver full capacitor on every cycle. 80% would be more reasonable. 3. The rated number of cycles for the battery is almost certainly exaggerated by best case assumptions.
Chevrolet/GMC dropped the S-10/Sonoma after 2003 and replaced it with a pickup 500 pounds heavier and I assume slightly larger to avoid CAFE restrictions.
1. Session establishment in the face of in band adversaries adding noise to the channel. Currently TCP connections can be trivially reset by an in-band attacker. I think resilience to this necessarily binding security to the network channel can be a marginally useful property in some environments yet is mostly worthless in the real world as in-band adversaries have plenty of other tools to make life difficult.
Doesn't IPSEC protect against this?
2. Efficient Multi-stream/message passing. Something with the capabilities of ZeroMQ as an IP layer protocol would be incredibly awesome.
I'm sure HP has been staring this one down forever, saying "We sunk all this money into Itanium, there's no way we can abandon it."
This does not have to be attributed to the sunk cost fallacy. The economics could simply be, "Supporting Itanium at this level will yield the lowest loss."
My Pentium II PC has 1GB of ECC RAM and 4+ TB of disk you insensitive clod!
It started out as a Celeron 300A but I upgraded it to a 1.2GHz Pentium 3. The Celeron 300A now has 384MB of ECC RAM and acts as my BSD router and firewall.
Inexpensive used RAM and parts are actually pretty easy to find for these systems.
USB based parallel and serial adapters have much lower performance than bus based interfaces. They only work in some cases. Interfacing to a microntroller board via USB solves this problem if legacy serial or parallel access on the PC is not required and low level programming on the microcontroller board is acceptable.
I use PCI or PCIe serial and parallel adapters instead of USB adapters for legacy applications.
I always hated the 8051 series but would have used an embedded x86 if available.
I have been using PIC in this application for years but am looking to switch to bare metal ARM so I will have a unified instruction set from the bottom to top. One disadvantage in some cases though is that most or all of the lowest end ARM embedded processors draw a lot more power.
Niven's World out of Time story had a plausible method for boosting the Earth to a higher orbit. Drag it behind a gas giant. Moving the gas giant itself was a bit more of a problem, but he had this magical planetary sized fusion rocket motor that used the gas of the gas giant as its fuel.
And then the Girls screwed it up and parked Earth in the wrong orbit. Even in the future there is a place for women drivers.
Some sound cards support bandwidths up to their Nyquist frequency making them useful in instrumentation applications. That says nothing of course about the analog circuits and transducers they are connected to which will not be optimized for operation at ultrasonic frequencies.
Unless it is disabled which may not be possible on some hardware, system management mode can easily generate at least 2 orders of magnitude more latency with a low end starting at just 100us. Even without system management mode, poorly written drivers can cause havoc.
When I had to deal with trying to use desktop hardware in real time applications, I qualified it with a simple test routine which toggled a visible I/O pin in response to an interrupt and measured the latency externally on an oscilloscope. The visual histograms were very informative. System management mode was a killer but access to I/O devices like mass storage or networking was often as bad.
I look forward to doing the same test on embedded ARM hardware running Linux or BSD in the near future but I suspect my final solution will be to continue using custom programming on low end embedded controllers for local real time tasks. At least with ARM there is the possibility of having to deal with multiple processors and only one instruction set.
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What I always find annoying about this is that once I am above 300 MHz or so where probing is easy, I am more interested in signal integrity issues where a high bandwidth low sampling rate sampling oscilloscope would be more cost effective than a lower bandwidth higher sampling rate real time oscilloscope yet the former are nonexistent and the later are too expensive.
This works right up until the time that it does not and you need to figure out what is wrong. This can be especially vexing if dealing with noise.
No expensive oscilloscope is needed for this either. Most problems are at 100 MHz and below.
I find that this is usually a probe limitation rather than an oscilloscope limitation.
The most useful oscilloscopes I use are either 100 MHz and below where passive x10 probes are still acceptable for general purpose use or 200 to 500 MHz depending on oscilloscope input capacitance where the fastest x10 passive probes still work probing 25 ohm circuits but in the later case, ground lead length becomes an issue.
My fastest oscilloscope for the later case is only 300 MHz.
The "1960s analog plug-in-based mainframe that is a '70s hacker dream scope" that he mentions might be pretty good. I have a few 400+ MHz similar oscilloscopes which have capabilities not readily duplicated in modern equipment.
I still do this for debugging software. An oscilloscope is great for getting an idea of the minimum, maximum, and distribution of interrupt latency and subroutine run time.
I forgot to include my impedance bridges in my list. A good LCR meter that can measure Q and D can be invaluable.
This is going to depend a lot on what kind of electronics you do. Since I do mixed-signal work, oscilloscopes are invaluable. I have 10+ but only a couple will fit on my workbench at a time although I have carts for them. They are all old enough to drink.
1. Weller Magnastat temperature controlled soldering iron. I have a vacuum desoldering head for it also.
2. 2 or more function generators.
3. 2 or more pulse generators and leveled sine wave oscillators.
4. 2 dual output tracking power supplies plus some other power supplies.
5. 3 bench multimeters and a pair of 4 and 5 digit handheld multimeters. These can measure temperature as well.
6. 3+ universal timer counters. Two of my analog oscilloscopes include this capability.
7. 2 combination analog and digital 2 channel 100 MHz oscilloscopes. Of the oscilloscopes I have, I use these the most. I actually have 4 like this but tend to use them in pairs.
8. 2 channel 300 MHz DSO. This has word recognition triggering so it is my current substitute for a logic analyzer.
9. Small 100 MHz bench analog oscilloscope which usually has a curve tracer installed.
10. Big 400 or 500 MHz bench oscilloscope that may be analog, analog storage, or digital depending on what I am doing. 4 channel dual sweep or even dual delayed sweep capability means these can effectively be two oscilloscopes in one and they can do things I have not seen any modern oscilloscope do.
11. If necessary I, break out the 1 to 14 GHz analog sampling oscilloscope plug-ins. This makes great eye diagrams although my analog oscilloscopes can do that up to 400 MHz.
12. A big two output isolation transformer for working with off-line switching power supplies.
The one thing I am missing which I would like is a fast waveform acquisition digital storage oscilloscope that can make histogram waveform measurements although I can do that with any of my analog oscilloscopes pretty well if dealing with standard deviations. This is one area where an old analog oscilloscope can beat out an inexpensive digital storage oscilloscope.
Those in the know will recognize that I have a lot of old Tektronix equipment and some of the model numbers. I wish their new products were as good.
They are serial in respect to how the data has to be reassembled to compensate bit skew at the receiver. With a parallel bus the bit skew is less than the bit timing so all bits can be latched simultaneously from the same clock. With a serial bus like HT, QPI, the wider versions of PCIe, and more recent DRAM buses, the bit skew is greater than the bit timing so each lane has to have its own phased locked clock signal and assembling all of the bits together happens at a later stage. In practice either a clock embedded in each data line is used or a synchronous clock line for each small group of data lines but in the later case skew compensation is often still needed.
Integrated and discrete ECL is still used where the lowest jitter is needed.
Captain Renault: I'm shocked, shocked to find that gambling is going on in here!
[a croupier hands Renault a pile of money]
Croupier: Your winnings, sir.
Captain Renault: [sotto voce] Oh, thank you very much.
Once you have enough of a battery to give you the range you want, then the power density is not a problem. The only capacitors you need are for high frequency decoupling and they only need to be selected based on ripple current and design lifetime.
1. Need to add in the cost of the electricity.
2. The battery is not going to deliver full capacitor on every cycle. 80% would be more reasonable.
3. The rated number of cycles for the battery is almost certainly exaggerated by best case assumptions.
Chevrolet/GMC dropped the S-10/Sonoma after 2003 and replaced it with a pickup 500 pounds heavier and I assume slightly larger to avoid CAFE restrictions.
Doesn't IPSEC protect against this?
Isn't that what SCTP is for?
You're browsing it wrong.
This does not have to be attributed to the sunk cost fallacy. The economics could simply be, "Supporting Itanium at this level will yield the lowest loss."
I would attribute the failure of MIPS as well which was used in workstations to Itanium.
My Pentium II PC has 1GB of ECC RAM and 4+ TB of disk you insensitive clod!
It started out as a Celeron 300A but I upgraded it to a 1.2GHz Pentium 3. The Celeron 300A now has 384MB of ECC RAM and acts as my BSD router and firewall.
Inexpensive used RAM and parts are actually pretty easy to find for these systems.
USB based parallel and serial adapters have much lower performance than bus based interfaces. They only work in some cases. Interfacing to a microntroller board via USB solves this problem if legacy serial or parallel access on the PC is not required and low level programming on the microcontroller board is acceptable.
I use PCI or PCIe serial and parallel adapters instead of USB adapters for legacy applications.
That is all the encouragement I need. Let's do this.
I always hated the 8051 series but would have used an embedded x86 if available.
I have been using PIC in this application for years but am looking to switch to bare metal ARM so I will have a unified instruction set from the bottom to top. One disadvantage in some cases though is that most or all of the lowest end ARM embedded processors draw a lot more power.
And then the Girls screwed it up and parked Earth in the wrong orbit. Even in the future there is a place for women drivers.
Some sound cards support bandwidths up to their Nyquist frequency making them useful in instrumentation applications. That says nothing of course about the analog circuits and transducers they are connected to which will not be optimized for operation at ultrasonic frequencies.
http://www.clarisonus.com/Research%20Reports/RR001-SoundCardEval/RR001-PCsoundCards.html
Unless it is disabled which may not be possible on some hardware, system management mode can easily generate at least 2 orders of magnitude more latency with a low end starting at just 100us. Even without system management mode, poorly written drivers can cause havoc.
When I had to deal with trying to use desktop hardware in real time applications, I qualified it with a simple test routine which toggled a visible I/O pin in response to an interrupt and measured the latency externally on an oscilloscope. The visual histograms were very informative. System management mode was a killer but access to I/O devices like mass storage or networking was often as bad.
I look forward to doing the same test on embedded ARM hardware running Linux or BSD in the near future but I suspect my final solution will be to continue using custom programming on low end embedded controllers for local real time tasks. At least with ARM there is the possibility of having to deal with multiple processors and only one instruction set.
Even more scary are recent embedded devices which use low retention time NAND Flash for firmware storage and copy into RAM before execution.