EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: txescientist on April 29, 2016, 09:04:59 pm
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I made up this joke, please tell me how good or bad is it? :-/O
-What does microprocessor say when there's no EPROM around?
-nop nop nop
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I made up this joke, please tell me how good or bad is it? :-/O
-What does microprocessor say when there's no EPROM around?
-nop nop nop
Do I find it funny ?
NOP NOP NOP
Please ERASE the joke, in the UV EPROM eraser.
Why did the EPROM cross the road ?
To avoid your jokes.
One day, txescientist in a FLASH of inspiration made a joke. Fortunately the FLASHES erase function allowed us to delete it, permenantly.
In future, please encrypt all future jokes (so no one can read them, even accidentally), and then send them to eraseWITHOUTreading@nowhere.nop.nop.nop
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:-DD
In before the thread devolves (even more) into discussions of floating inputs and nondeterministic blah blah blah.
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What did the x86 processor say when the flash memory is empty?
PUSH, PUSH, PUSH...
Stack overflow.
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You want bad jokes??
- Why did the CIA ban Chinese microcontrollers?
- They were full of SPIes
- Why do felines make great electricians?
- They're rated CAT IX
- After some back and forth, Armstrong was arrested today
- He got caught red-handed as a joule thief
I'll be here all night... :scared:
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:-DD
In before the thread devolves (even more) into discussions of floating inputs and nondeterministic blah blah blah.
:blah: :blah: :blah:
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I always have trouble looking for laptop ram, desktop ram is pretty easy to find, but laptop ram is just impossible. No matter how many lights I have turned on. it's always so dimm
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The very first circuit I built with a Z80 CPU was an overly elaborate 16 bit counter. Wire the data bus low and it reads NOP (00h), and never writes to the bus (so it can be hard low, don't even need pulldowns). A15 then buzzes at a modest frequency (something like 20Hz, for a 4MHz CPU clock and, however many T-states a NOP was, 3 cycles I think?).
Tim
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My CringeMeter 2000 on this subject: :bullshit:
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My CringeMeter 2000 on this subject: :bullshit:
Consider it your... punishment.
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Q: Why must you always wait for a long time before putting equipment back into service after cleaning contacts, circuit boards etc. with alcohol?
A: It needs to sober up, because: A potched Watt never toils!
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My CringeMeter 2000 on this subject: :bullshit:
Knock, knock...
Who's there?
Meter.
Meter who?
Meter near the lamp, she'll tell you the amp! :-DMM
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A volt, an amp, and an ohm walk into a bar...
(that's all I got...)
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A volt, an amp, and an ohm walk into a bar...
(that's all I got...)
It's got potential... you should charge ahead... the result might be, electrifying!
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PCB Layout Engineer: One of the few professions from which you can be fired for missing the bus.
Q: Why do transistors tend to live longer than resistors?
A: Most likely it is due to their active lifestyles.
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Where is Dave's 'no' button when you need it? :palm:
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Why did the Xilinx race team up with Alterans to attack planet Xeon and failed?
Their Intel said they were unARMed but turned out they had Atom.
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My CringeMeter 2000 on this subject: :bullshit:
Yes but is your CringeMeter working correctly, or is it just a FLUKE ?
The very first circuit I built with a Z80 CPU was an overly elaborate 16 bit counter. Wire the data bus low and it reads NOP (00h), and never writes to the bus (so it can be hard low, don't even need pulldowns). A15 then buzzes at a modest frequency (something like 20Hz, for a 4MHz CPU clock and, however many T-states a NOP was, 3 cycles I think?).
Tim
One or more, very old microprocessor sets, used that very principle, to allow hex or switched data, to be entered. I.e. it made the microprocessor issue successively increasing addresses, ready for ram to be filled, by the user.
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This topic is so negative :palm:, that overflowed to pure awsome :bullshit:
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My CringeMeter 2000 on this subject: :bullshit:
Yes but is your CringeMeter working correctly, or is it just a FLUKE ?
The very first circuit I built with a Z80 CPU was an overly elaborate 16 bit counter. Wire the data bus low and it reads NOP (00h), and never writes to the bus (so it can be hard low, don't even need pulldowns). A15 then buzzes at a modest frequency (something like 20Hz, for a 4MHz CPU clock and, however many T-states a NOP was, 3 cycles I think?).
Tim
One or more, very old microprocessor sets, used that very principle, to allow hex or switched data, to be entered. I.e. it made the microprocessor issue successively increasing addresses, ready for ram to be filled, by the user.
That would be the RCA 1802, with its built-in Load mode, no additional hardware (other than some switch or keyboard design) needed to load programs. You can also hard wire the pins on it and make an LED flasher that draws significantly less current than an LM3909 flasher.
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That would be the RCA 1802, with its built-in Load mode, no additional hardware (other than some switch or keyboard design) needed to load programs. You can also hard wire the pins on it and make an LED flasher that draws significantly less current than an LM3909 flasher.
The one I was thinking of was the SCAMP (based on the SC/MP, with slide switches and LED's, on a big PCB). But I can well believe there are many others.
I've done it myself by accident (the read/write/enable lines or something were messed up), so it read "NOP's" all the time, until I fixed it. (Actually it was probably whichever instruction is produced by all $00's or all $FF's, being read. Which is sometimes a NOP. Depending on the MCU's instruction set).
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That may have been about all 2 of them then. I'm sure you can rig equivalent circuitry on others, but the 8080, 8085, Z80, and 6502 definitely did not have built in load mode. Only problem with the 1802, you can; just tie all data lines high or low - 00h is IDL and FFh is SMI (subtract memory immediate). NOP on the 1802 is C4h. 1802 was static CMOS process, so you could clock it right down to 0 and it would draw nanowatts until you started the clock back up again and pick up where it left off. It was also available in radiation hardened versions and saw duty in several OSCAR satellites as well as some space probes like Galileo. If you recall way back when they did a mission to swap out the computer on the Hubble telescope - I think the one they took out was a system built around the 1802.
I have a soft spot for the 1802 - it was my first computer, which I still have and it still works. But even earlier than that, it was an article on the predecessor chip, the 1802 (essentially the same but the ALU and registers were in two separate DIP packages instead of a single 40 pin DIP), in a 1974 Radio-Electronics or Elementary Electronics that pushed me towards the digital side of electronics. The article explained the details of the CPU's operation and though I was but 9 or so at the time, I read and reread that article until I understood it.
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This thread is out of control. Better get my PID.
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That may have been about all 2 of them then. I'm sure you can rig equivalent circuitry on others, but the 8080, 8085, Z80, and 6502 definitely did not have built in load mode. Only problem with the 1802, you can; just tie all data lines high or low - 00h is IDL and FFh is SMI (subtract memory immediate). NOP on the 1802 is C4h. 1802 was static CMOS process, so you could clock it right down to 0 and it would draw nanowatts until you started the clock back up again and pick up where it left off. It was also available in radiation hardened versions and saw duty in several OSCAR satellites as well as some space probes like Galileo. If you recall way back when they did a mission to swap out the computer on the Hubble telescope - I think the one they took out was a system built around the 1802.
I have a soft spot for the 1802 - it was my first computer, which I still have and it still works. But even earlier than that, it was an article on the predecessor chip, the 1802 (essentially the same but the ALU and registers were in two separate DIP packages instead of a single 40 pin DIP), in a 1974 Radio-Electronics or Elementary Electronics that pushed me towards the digital side of electronics. The article explained the details of the CPU's operation and though I was but 9 or so at the time, I read and reread that article until I understood it.
I'm also very interested in the 1802. I also have a soft spot for it, despite the fact I have never been involved with it, so far.
I still really admire computers made/programmed with just switches and Leds (+ possibly hex keyboards and seven segment displays). They seem to mark the start of the (especially home/hobbyist) microprocessor revolution.
They were typical (but very rare) electronics magazine projects of the 1970's, using various different microprocessors of the time.
The super low power consumption, is still an amazing concept. Somehow modern devices (because of increasing leakage currents, as they get smaller, I have been led to believe), are NOT necessarily so good, as the older CMOS parts. But there do seem to be possible exceptions. So if they (IC producers) go for that (low power consumption), they can still do it.
E.g. Devices which need to run for 10+ years on a small lithium battery, and yet still have a degree of computing processing ability available. Such as smart power meters (maybe).
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CDP1802 was used in Yugoslavian radiation detector, because it is very reliable under high ionizing radiation. Also, read it somewhere that 4 of them were used in a satellite :-+. Also, it was used in Yugoslavian home computer PECOM 32 and 64.