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  1. Z

    Fortran Fortran Forum

    If you want to access the 5th element of X (FORTRAN arrays start at 1, by the way, or at least they used to when I was programming), then it's simply X(5). for instance: do 100 i = 1,5 print ( *,1000 ) X(i) 100 continue stop 1000 format ( 1x, f6.2 )...
  2. Z

    Fortran Fortran Forum

    parameter (n=5.0d0) real*8 X(1,n),Y(1,n),sum1,sum2 This doesn't look right to me... You appear to be defining n as a real number (floating point), then using it to define an array. Also, why are you defining X and as two dimensional arrays? Surely X(n) and Y(n) would be...
  3. Z

    Fortran Fortran Forum

    Have you tried putting 7 or 8 leading spaces before your code lines yet? Columns 1 to 6 are reserved for labels and the continuation character. Obviously something like 123 continue Wouldn't need leading spaces in front of the 123, but does need the spaces between the 3 of 123...
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    Running a f90 code in f77 compiler

    Is the f90 source in freeform format? (i.e. not tabbed out to column 7). Does the f77 compiler support freeform? How much code is there? 1k lines, 10k, 100k? or more?
  5. Z

    Current limiting resistor for led on 7408 gate output

    Gosh. Here I am, looking the TI ttl databook, what do you know? The 7408 has a totem pole output. In other words, it has an active pullup and an active pulldown. For standard ttl, the pullup doesn't pullup very far, 2.4V at 400uA... not much compared with a CMOS 74hc08... So it's...
  6. Z

    With FORTRAN I may program Microcontrollers ?

    Depends on the micro... [Broken]
  7. Z

    Running a f90 code in f77 compiler

    Have you tried running it through the compiler to see what error messages it generates?
  8. Z

    Fortran Problems reading binary file in FORTRAN

    Have you checked that it creates a file of the correct size before you try to read the data back?
  9. Z

    NASA Nasa, Ares and the gratuitous Monty Python joke

    Obviously time to get the ouija board out to consult dear old Wernher... Pity they destroyed the designs for the Saturn V back in the 70s... "Oh, we'll never need those ever again"...:rofl:
  10. Z

    DC generation back during Edison

    There is a way to transform DC up & down... It's called a static inverter. The power line under the English Channel that connects the UK power system to France uses DC to avoid having to synchronise the generators on either side of the link. This possibility didn't exist before the...
  11. Z

    Quartz resonator

    Startup time applies to crystal oscillators, not to filters. The low power crystals used in watches have very long startup times.
  12. Z

    DC generation back during Edison

    Instead of using an alternator driven by a steam engine to give AC, he used a dynamo driven by a steam engine to give DC. The problem with DC is that you can't use transformers to increase or decrease the voltage, which is what makes grid power transmission so much more efficient by reducing...
  13. Z

    Visual Basic Help

    Are you attempting to do arithmetic on text? (i.e. a string?). Convert the text to a double before attempting the divide.
  14. Z

    Help with asm: include and compilling

    From that f84temp.asm template file I mentioned above: list p=16F84 ; list directive to define processor #include <> ; processor specific variable definitions
  15. Z

    Help with asm: include and compilling

    The other thing that springs to mind is that there's a load of template files in a subdirectory of MPLAB. They're found in a directory something like "C:\MPLAB\template\code" If you have a look around using windows explorer, you'll find them. There's a template in there that is intended...
  16. Z

    Help with asm: include and compilling

    If you investigate the Help section of MPLAB, you'll find (if you dig deep enough) a list of the error codes generated by the assembler. I don't have MPLAB on this pc so I can't help much more than that.
  17. Z

    Recommended Microcontrollers?

    PICs are ok if you're developing in C. The microchip assembler syntax sucks in my opinion.
  18. Z

    Capacitance bridge

    So far as I'm aware, bridges with reactive elements are energised with alternating current rather than d.c. (as per the battery). The detector will then need to be sensitive to A.C. There are lots of weird & wonderful bridge circuits, the Maxwell Bridge, the Hay's Bridge, Owen's Bridge...
  19. Z

    Recommended Microcontrollers?

    There's always the ubiquitous PICs... so many to choose from. And "free" downloads of C compilers to suit.
  20. Z

    Drilling PCB using Microcontroller

    A European magazine called "Elektor" did a kit for a computer controlled milling machine last year.
  21. Z

    Fortran NEED HELP with fortran compiler

    It appears to be compiling two files: simple.f95 and sample1.f90. Which gives it two _MAIN_ modules which the linker doesn't like. Is there something wrong with your make or project file?
  22. Z

    Quartz crystals and voltages

    I suspect that if you applied kV to a quartz crystal it would fracture. The manufacturers list maximum drive voltage in their specifications. Watch crystals are particularly sensitive, being designed to work with very low power levels.
  23. Z

    Help with SMT diode selection

    Sounds ok to me. The only problem with a schottky is likely to be the reverse leakage, which is considerably higher than that for an ordinary Si diode. Probably won't make much difference in your application, but if it does, then reduce the value of pullup/pulldown resistors.
  24. Z

    Engineering 3 simple circuits

    Does this post from NoTime mean nothing at all to you? It's a very big hint...
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    Help with SMT diode selection

    The sot23 has the advantage over the SMA in that it won't roll off the board...
  26. Z

    High voltage magnetic field

    5mm spacing from a 3kV over head conductor sounds extremely dangerous to me... Are you going to leave your wire there when they turn the powerline back on? If so, I'd stand well away from your apparatus... it won't be the magnetic field that fries everything, it'll be the arc from the...
  27. Z

    C putchar() and getchar()

    If you're running that in a dos box under Windoze, then EOF is defined as Control Z on standard in. Try that.
  28. Z

    General Oscillator Questions

    The transistor provides the gain needed to produce oscillation. In that diagram, it's shown as a JFET. The voltage levels across the resonant circuit are unlikely to produce damaging back emfs when the circuit is switched off. Bear in mind that the circuit does not show any of the d.c...
  29. Z

    Help with SMT diode selection

    BAV70 is a dual diode in sot23. It's common cathode, but common anode duals are also available.
  30. Z

    Gas to power stoves and heat homes in rural areas

    "Natural gas" is mostly methane. Portable containers usually hold butane or propane. Static containers for domestic heating are filled with LPG (liquified petroleum gas) in this country.