Re: Motion LS800 table HD failure at 14,000 feet

[[email protected]]

In rec.aviation.misc Peter > wrote:
> Flash alternatives (I believe it is a 1.8" HD inside) are extremely
> costly, around USD 2000 for 8GB, and I wonder how successful it would
> be to put in a 4GB SD card (for which there is a slot), put all maps
> on that, etc.

I recently did something like this at work, for somewhat the same
reason. In my case, I had a couple of accelerometers connected to a
data acquisition card in an old desktop PC. The accelerometers got
bolted into a car that was going to be crash-tested, and the PC got
to go along for the ride. We decided that a rotating-platter drive
probably wouldn't cut it, and looked for alternatives.

What we ended up using was an "IDE 4000" series flash drive from
M-Systems. This is flash memory in a package with an IDE connector;
it looks and works just like a regular hard drive to the operating
system. M-Systems sells a couple of different lines of drives - the
ones that support the latest and fastest interfaces (Ultra ATA and
SATA) are indeed expensive - about US$850-$900 for 2 GB. The IDE
4000 series is not quite as fast but is much cheaper; around $200-
$250 for 2 GB in a 3.5" drive. We bought a 2 GB drive from Digi-Key,
http://www.digi-key.com/ - current catalog page
http://dkc3.digikey.com/PDF/T063/0865.pdf .

This system was so old that it was running Windows 98. With the
regular hard drive still in the system, I uninstalled all unneeded
programs and got the total installed size of the system down to well
under 1 GB. I then installed the flash drive and did a drive image
copy from the hard drive to the flash drive (think Norton Ghost or
similar). Then I removed the hard drive and let the system boot up
on the flash drive... no problem. Benchmarking programs showed that
the flash drive was indeed slower than the hard drive, but neither
Windows nor the data-acquisition software seemed to care - I could
still log data to the flash drive as fast as I needed to. The
computer and the flash drive survived the wreck and everyone was
happy.

> The problem is that Windoze itself accesses various bits of the HD
> anyway, and does anyone know which bits, and can they be moved to
> the SD card?

Microsoft knows but they ain't tellin'. I think it's possible to
split things up like this, but it will take a lot of trial and error
to make sure you've got everything you need on the SD card. Even then,
if you accidentally click on the wrong icon or something, Windows may
still try to spin up the hard drive. If you have a real Windows
installation CD (not a "restore" CD provided by the computer
manufacturer), it might be interesting to remove the hard drive from
the PC, install the SD card, boot up the Windows install CD, and see
if you can convince it to install onto the SD card instead. If that
doesn't work, then buying a flash drive that has an IDE interface,
installing it along with your current hard drive, and doing a disk copy
from your current drive to the flash drive (assuming you can fit
everything onto the flash drive) will probably work. If there aren't
enough hard drive connections on your portable PC, you may have to
temporarily install both drives on a desktop PC to do the drive copy,
then put the flash drive back in the portable.

I hope this helps!

Matt Roberds

[Jim Macklin]

Checkout military spec and mountain climbers.


"Peter" > wrote in message
...
|
| wrote
|
| >Microsoft knows but they ain't tellin'. I think it's
possible to
| >split things up like this, but it will take a lot of
trial and error
| >to make sure you've got everything you need on the SD
card. Even then,
| >if you accidentally click on the wrong icon or something,
Windows may
| >still try to spin up the hard drive. If you have a real
Windows
| >installation CD (not a "restore" CD provided by the
computer
| >manufacturer), it might be interesting to remove the hard
drive from
| >the PC, install the SD card, boot up the Windows install
CD, and see
| >if you can convince it to install onto the SD card
instead. If that
| >doesn't work, then buying a flash drive that has an IDE
interface,
| >installing it along with your current hard drive, and
doing a disk copy
| >from your current drive to the flash drive (assuming you
can fit
| >everything onto the flash drive) will probably work. If
there aren't
| >enough hard drive connections on your portable PC, you
may have to
| >temporarily install both drives on a desktop PC to do the
drive copy,
| >then put the flash drive back in the portable.
|
| Yes, this is what I would do too.
|
| One could use Truimage to take a snapshot and then restore
that onto
| the flash drive.
|
| I need at least 8GB and in 1.8" format, and it doesn't
seem to be
| available.
|
| The other thing is that the BIOS doesn't support the SD
slot as a
| bootable block device, so one couldn't (AFAIK) install
windoze on the
| SD card directly.
|
| I am just curious what "altitude" solutions the GA vendors
are
| offering... they can't all pack up at 14k, or can they????
I am sure
| plenty of American non-pressurised pilots fly high up,
with oxygen,
| just like I do.

[[email protected]]

In rec.aviation.misc Peter > wrote:
> I need at least 8GB and in 1.8" format, and it doesn't seem to be
> available.

I think M-Systems has flash disks in 1.8", but Digi-Key doesn't carry
that line. I don't know how much storage they offer in 1.8".

An alternative might be to buy a 2.5" or 3.5" IDE flash disk and put it
in an external USB enclosure. This will probably work a lot better if
your portable PC has USB 2.0 ports and you use a USB 2.0 enclosure.

> The other thing is that the BIOS doesn't support the SD slot as a
> bootable block device, so one couldn't (AFAIK) install windoze on the
> SD card directly.

You might have to install it somewhere else, image it over to the SD
card, and then use something like Smart Boot Manager
http://btmgr.sourceforge.net/about.html to boot from the SD card. I've
used SBM on a floppy to boot various installation CDs on an older PC
that didn't have a BIOS setting for booting from CD. Of course your PC
probably doesn't have a floppy, so you'll have to be creative.

> I am just curious what "altitude" solutions the GA vendors are
> offering... they can't all pack up at 14k, or can they????

I can think of a few reasons this wouldn't work, like condensation,
poking holes in it with the stylus, and dying of embarrasment if anyone
sees it, but how about a big Ziploc-type plastic bag? Wait until 10000
or so, put the PC in the bag, seal it up, and the PC has a nice little
pressurized compartment to live in. OK, having a bag failure take out
all of your navigation information probably isn't the best idea. Maybe
put a normal hard drive in a USB enclosure, then put the USB enclosure
in a Pelican case or similar and figure out a way to seal around the
cable.

Matt Roberds

[Doug Vetter]

Peter wrote:
<snip>
> Yesterday I got another copy of the U.S. Flying magazine through my
> door and looking through it I see loads of vendors selling aviation
> related software products (Anywheremap etc etc) on the ls800. I just
> cannot believe that this issue has not come up before. It is as if
> nobody in the USA flies unpressurised above 14k feet, which I am sure
> has to be rubbish.

The reason more EFBs don't support a flash drive is that merely
replacing the hard drive with a big flash drive is not the proper
solution. The problem is compounded by the fact that most EFB vendors
are not embedded systems engineers. They simply want to treat the EFB
platform as a standard PC on which they install the OS (Windows), their
application software (flight planner, etc), and be done with it. If you
want a reliable EFB solution, that is clearly not the answer.

The problem is flash memory excels only as a read-only medium due to its
write cycle limitations (both in terms of speed and number of cycles).
If you're updating your application data on the flash every 28 days (or
even once a week), that's no problem, but if you install the OS such
that it operates directly from the flash drive, the constant writes to
the swap file and other meta data will kill the flash in short order.

The benefits and limitations of flash memory are nicely outlined here:

http://en.wikipedia.org/wiki/Flash_memory

In order for a flash drive to effectively replace a hard drive in this
application, you have to do some engineering to load an OS image from
flash and execute it entirely in ram. AFAIK, Windows (the consumer
version at least) cannot do this.

-Doug

--------------------
Doug Vetter, ATP/CFI

http://www.dvatp.com
--------------------

[John R. Copeland]

"Peter" > wrote in message ...
>
>
> .... but it is a consequence of the lousy
> windoze memory management: no matter how much RAM you give it, it
> still uses the swapfile. The vintage Win3.1 didn't do this but
> everything since has done.
>
> Samsung have just announced a range of laptops which will use flash
> drives, and they are running standard windoze XP. I don't know what
> they do about the swapfile...
>

Did you intend to say that WinXP cannot run without a paging file?
That's would be incorrect, of course.