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This thread is privately moderated by Jack Crossfire, who may elect to delete unwanted replies.
Jan 27, 2007, 04:02 AM
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King of JTAG

After 2 weeks of mane hair removal, imminent bankruptcy, 3 programming circuits, 10,000 Win2000 reboots, and EE purgatory, the STR9's JTAG works. Got good return values for a chip erase and a configuration register write. The flash banks are now supposedly reordered so it boots into the 32k and can use a bootloader there to program the 256k.

All the success was achieved by custom software in Linux. The CAPS tool was a complete waste of time. Still much 2 do: running hello world, developing a bootloader, and programming the 256k flash.

In other news, was thinking about the Silicon Valley tech fad followers who are buying $500 bikes because they fold up, instead of a $200 electric scooter which takes up less space than the folding bike, because their corporate idol CEO rides a folding bike.

If there was a way to transport the copter on a scooter, we would have a pretty huge incentive to make the Razor E300 happen when gas hits $3.50 again, but the scooter doesn't have any cargo room. The copter is drastically cheaper to fly than the car is to drive.

Had 22 min of good sonic booms with the copter, but the lowest flight time ever. They seem to come easier in warm, moist conditions. Bring it up to 150 ft, idle the throttle and pitch hard forward, the combination of rapid descent and forward movement gets those blade tips up to 650mph.

kiwipedia wrote:
> the 747 broke the sound barrier during certification tests.
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Jan 28, 2007, 03:16 PM
I under stand the sonic boom but at 650 mph tip speed at ground level stander day what is the dv ( differance in volacity ) of the air flow over the top side of the blade and at which point dose the compesibility become a problem, the air over the top curve of the blade will reach the speed of sound be for the advancing forwrad blade dose and will not that cause a delta p and cause the blade to do some funky stuff. just woundering.
Jan 30, 2007, 09:18 PM
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According to kiwipedia:

As an aircraft approaches the speed of sound, an effect known as wave drag starts to appear. The air reaches supersonic speed locally over an area on the top of the wing, and this local supersonic region ends in an oblique shock wave, which becomes nearly normal on the wing's upper surface. The losses of the normal shock wave increase drag.

The Corona normally tries as hard as possible to pitch up in forward flight and the shockwave probably only happens on the very end of the blade, so the effect of shockwave drag is probably negligible. It definitely seems to fight back when the chops start, and sometimes feels like it's rolling towards the advancing blade.

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