mungewell

Agents of the Revolution
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Posts posted by mungewell


  1. So let's say I have a audio sample I just took and shoved it into a buffer. It's say, 1/50th of a second long.. Now I compare that signal with a mathematically generated sine wave of a target frequency. Is it the superposition(for lack of a better word) of those two that becomes the 'line' in the spectrograph?

    If I remember correctly (at it's been a really long time) you would first perform a hamming window function on the buffer to remove high frequency components at the start/end, perform the FFT and then use the amplitude of each 'bucket' as a line on the spectrograph.

    Munge.

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  2. It gets to the options screen and when it boots, it just hangs, everytime.

    Did you try another LiveCD/Distro?

    It could be that the Xorg is crashing with your video card, is there an option to select VESA at boot prompt? Does text mode boot work OK?

    Try a memory check (Ubuntu CD or UBCD).

    Could be that CD drive is toast, I have a T21 which a knackered drive which won't boot from external USB CD. So I have to start boot on internal and then eject that just after kernel is loaded...it can then proceed to load from USB CD.

    Mungewell.

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  3. I am curious if there is a way to use USB to my advantage. Is there a way to create something bootable that can input password for me?

    Interesting concept.... and yes it would be moderately easy to have a USB device pretend to be a keyboard and throw some characters out. This is pretty much what the 'ubikey' security dongle does. Should be doable with a small micro running as a USB slave.

    However, if you need to log in then you will need a pre-determined username/password pair. It might just be easier to 'attack' the auto-run function to start the OSK. If autorun is disabled, I wonder what other methods there are at getting OSK up and running.... why not just plug in a real keyboard?

    If you have IP access to the machine, why not just enable remote desktop....

    Mungewell.

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  4. Is there software that would let me basically blast the airwaves (Up to the 36DbM FCC limit)

    Why worry about the FCC Limit? If you are intentionally interfering with communications you are already working outside the FCC Part 15 license.

    You don't say what your motivation is...

    Munge.

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  5. With using a VPN you have two layers to get through until 'the goods are out'. You (presumely) have different user/passwd pairs for VPN access and RDP/Domain access.

    You can also use the VPN identity to limit which machines that this person can RDP into, rather than exposing all of the internal network to RDP.

    Some company policies dictate that all traffic from a corporate owned machines *MUST* travel through a VPN/company network and will not allow associatation with a 3rd party network except to bring up a VPN tunnel.

    Munge.

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  6. It's possible the that ATA password is also set on the hard-disk (if it does not read on another machine). This is quite often the same as the BIOS password, so can be used to brute force the BIOS if it is really (!!) needed.

    Generally it is probably easy just to buy another machine....

    Mungewell.

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  7. Under Ubuntu/Debian the is a package call ifscheme.

    http://packages.ubuntu.com/jaunty/ifscheme

    You can create alternate wireless networks listed in /etc/network/interfaces. It will scan wireless with 'essidscan' and bring up the appropriate network (first found) when you do an 'ifup eth1' (for example). It does not auto-detect loss of connection, you have to manually 'ifdown' and 'ifup' if you change location.

    Works for me OK.

    Mungewell.

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  8. The 'best' way depends on how much current you need at the low voltage, is this powering a circuit or just acting as a reference point?

    For a reference voltage, you can use a zener diode with an inline resistor. In nasty ASCII art:

    +9V --==R==--+----{<|--- 0V (where the '+' is the reference voltage)

    The zener will regulate to it's marked voltage providing that the current through it is correct (normally around 5 to 10mA), the resistor provides most of the voltage drop (at the chosen current) and the zener will 'fine tune' the voltage smoothing out any fluctuations in voltage/resistance.

    This only works if there is a minimal/constant current draw from the '+' point, as too much variation in current here will affect the voltage, hence this is a 'reference circuit".

    The amount of energy used is the 'power lost' by the circuit (normally as heat). If the currents are low, the power loss will be low too, even if the voltage drop is large.

    Cheers,

    Mungewell.

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  9. Baaa..... I hate you all!!! I'd love to go again this year, but can't due to other commitments.

    Watch out for the guys from the Calgary LUG, they're really mean and keep ragging on me being a wimp.... ;-)

    Mungewell.

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  10. It runs Windows Mobile 5 but doesn't have a wireless card.

    Do you have a Data plan on your cell? Normally a incoming DUN/Bluetooth connection would call a 'special' number and then enter PPP mode with packets routed to the internet. Which provider are you on? Telus requires a username/password related to the phone's serial number (IIRC)

    This is what I did with this unit:

    gallery_7512_113_9080.jpg

    Cheers,

    Mungewell.

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  11. It may be that it is allocated as a SCSI device, in which case it would show up as '/dev/sda1...n' (rather than '/dev/hda1...n').

    Have a look in the system log ('/var/log/syslog') or at the output of 'dmesg' to confirm.

    Cheers,

    Mungewell.

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  12. Looking at the circuit you linked:

    bug5c.gif

    Every thing to the Left of CX is a mic and preamp, the output of this slightly affects the frequency (hence FM modulation) of oscillator built around the BC547 and the BC557 is a power amp.

    If you are wanting a pulsed output (or something) you would probably be better off using a small micro (8 pin PIC or the like) to generate the 'tones' and couple this with a oscillator/power amp. With a bit of care in the design you may be able to use the PIC and/or PLL as the oscillator, providing you can get enough frequency stability out of it.

    BTW if you *really* want to piss some people off, use a slightly offensive message in morse code (with 2600Hz tone of course) in the 2m HAM band, you WILL be hunted down by a horde of angry old men ;-)

    Have fun.

    Mungewell.

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  13. It may look like a dumb question, but how do I do a CUPS raw file dump?

    This page tells you how to share a raw print queue (ie. CUPS does not attempt to process the image data) with a Windows machine:

    http://etc.nkadesign.com/Printers/QL550LabelPrinterRaw

    You then set the CUPS URI destination to 'file:/.... something', I used a file in the tmp directory, relevant part of my printers.conf is below. You may also need to set the 'FileDevice Yes' option in cupsd.conf to allow dumping to file.

    <Printer QL570_File>
    Info Dump to file
    Location local
    DeviceURI file:/tmp/ql570.raw
    State Idle
    StateTime 1238054724
    Accepting Yes
    Shared Yes
    JobSheets none none
    QuotaPeriod 0
    PageLimit 0
    KLimit 0
    OpPolicy default
    ErrorPolicy retry-job
    </Printer>

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  14. @mungewell: CMYK looks interesting, is there anything I could you to simply display the pixels assuming that they are CMYK codes?

    Once you find where the data block is (if it is of a fixed size) you could extract the particular block of bytes from the capture and either:

    1) Convert then programmatically into a format you could view using C, python, perl or the like.

    2) Use imagemagick's convert tool, which apparently has a raw CYMK mode (you have to specify image size and depth). see http://imagemagick.sourceforge.net/http/www/formats.html

    Which part of the CUPs system are you working on? Data generation (ie printer driver), or sending the data to the printer? Can you just netcat the raw capture (from Windows printer) to the printer's IP/Port?

    Mungewell.

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