REFLECTOR: New Collection and Control Hardware

Thu May 4 09:07:34 CDT 2006

Personally, I like to mount the plane of the HDD vertically.  With the 
new drives coming out these days, it's probably not necessary.  The new 
ones have accelerometers that park the heads if they sense a large shock.

Also, don't go overkill on hard disk capacity.  The new 750Gbyte hard 
drives available these days are getting into scary territory.  The 
technology used is a PROBABILITY that the bit you are reading is a 1 or 
a zero.  The bits are so close, and they are magnetic signatures, that 
they tend to migrate towards or away from each other.  Go for a high 
quality five year warranty drive with the lowest capacity you can find.

I'd say 20Gb is about right for Windows ... if you can find one that small.

There are several directions to go under Linux.  You'll have to research 
them yourself.  Wine is one of them, and virtual computing would be another.

However, once you go down that route the benefits of having the Linux 
system are lost.  It would be less trouble and more reliable to stay 
with native Windows.

The Compact flash will do okay.  How much you run the system will 
determine how long it will be till failure.  If I'm not mistaken flash 
is still gauranteed to about 10,000 writes.  Assuming 100 hours of 
operation per year, you might get five years before the flash wears out. 
  IBM also sells another solution.  It's called a MicroDrive.  It's a 
very small disk drive that fits in a CF slot.

Alex Balic wrote:
> Brian- about the HDD- do you think no matter how rugged it is it might crash
> without sufficient (designed for) air pressure to float the heads- that has
> been my concern, not random failure, but head crash. Although, I suppose
> that airliners pressurize to 8000 feet or something, so they work at that
> altitude anyway, just with a turbo, I plan to get up as high as possible,
> and will probably have trouble with the disk.
>  Have spoken to some Linux guys, no one seems to be able to help really, and
> the E-mon program will not work with Linux either, nor can I find any sort
> of alternate industrial monitoring app written in Linux so I guess I am back
> to trying to get XP on the CF card..... somehow, I was under the impression,
> that Linux would run XP programs, maybe that was W98 programs......
> 
> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
> Behalf Of Brian Michalk
> Sent: Sunday, April 30, 2006 1:46 PM
> To: Velocity Aircraft Owners and Builders list
> Subject: Re: REFLECTOR: New Collection and Control Hardware
> 
> One thing you may want to do is install a Linux with read only access to 
> the card.  It will help in two ways.  First, you'll wear out the CF if 
> it's read write.  This seems to be getting better all the time as CF 
> technology progresses.  Second, and more important is that it can't get 
> corrupted by power glitches taking down the machine.  Mount a /var and 
> /tmp partitions in ramdisk so the system functions like normal.  There 
> are a few tutorials on the net how to do this.  Snoop around the MP3 
> modders that put these Linux machines in their cars.  Lot's of good info 
> there that translates directly to our application.  I don't know how to 
> do this in Windows.
> 
> I've got two computers.  The Linux machine is an industrial embedded 
> board from Advantech with a healthy power supply.  The Windows machine 
> is for entertainment and other miscellaneous non-critical stuff.  It's a 
> 1GHz EPIA board that runs about 10 watts.  It's got a ruggedized laptop 
> disk drive.  For drives, I've found the best predictor of performance to 
> be a warranty.  If you buy a drive with a five year warranty you'll be 
> in good shape.
> 
> As far as helping out?  Well, I've got my hands full getting all of my 
> stuff talking right now, but I can offer advice wherever I can.
> 
> I've also got the PC-flight systems gyro.  They do provide the serial 
> protocol.  It's connected to the Linux machine where that data will be 
> offered on the SMBUS or LAN.  I intend to couple that to my autopilot. 
> I searched hard and long for an electric mechanical gyro with autopilot 
> output, but couldn't find one I felt was reliable or one that I could 
> afford.
> 
> Alex Balic wrote:
> 
>>Hey Brian-
>>I have a laptop in My XLRG connected to a 7" touch screen display- wanted
> 
> to
> 
>>possibly run Linux on there off of a 2GB CF card- to display engine
>>parameters for my Subaru- I am no computer genius, so now just have a
>>disassembled laptop that will put XP desktop up on the touch screen,
> 
> running
> 
>>from HDD but probably not enough room to install anything else to go to
> 
> the
> 
>>CF card- do you think you could lend a hand? Was going to use the PC
> 
> flight
> 
>>systems E-mon program, but would not be adverse to anything else that can
> 
> do
> 
>>the same thing.......
>>
>>Alex
> 
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