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Mir Up-loads








Miles Mann wrote:

> I was even able to upload JPG images of his family directly to his lap-top
hard
> disk.

I was pretty sure about it but I never understood how!
Now that all is history, can you told us how it was done?
Thanks in advance.

F.Costa, CT1EAT


****************************
MAREX-NA Mir file transfer testing

Sending Large packet files to the space station Mir is not easy, because of the
slow speed of the data link and your limited 9 minute window.
The Mir Kantronics KPC-9612 supports both 1200 and 9600 baud data rates.
We never had the opportunity to test the 9600 baud mode, even though
we had all of the resources (politics).

So all of our testing was limited to just 1200 baud.

For some of our testing, Mike Foale in 1997 on Mir configured his laptop to be
running Winpack software
and left the laptop running for long test times.
If you logged into the R0MIR port  with Winpack at both ends of the link
and issued the correct commands, you would see the directory
listing of the PC's disk on the Mir Space Station.
And you had the ability with Winpack to upload or download files directly to the
disk.

Lets assume we have a small JPG image of 150,000 bytes of data.
Each Byte = 1 character = 8 bits.
Each character gets encoded with 1 start bit and 2 stop bits.
This will make each character 11 bits long
11 bits times 150,000 bytes = 1,650,000 bits of data for one jpg image.
If we are sending data at 1200 bits per second, it will take 1375 seconds to
send one image.
or 22.9 Minutes.
And this time does not include the normal overhead of a simplex handshaking
loads.
The actual over-the-air time would be double.
The  JPG image I started with was 25,000 bytes.  I then shrunk the image down to
a postage stamp
and made it black and white.  Of course the quality dropped  but this was just
to prove
the ability to send an image and have it decoded correctly at the other end.
After the shrinking was competed I had a 3,000 byte file.
Uploading a 3k file to Mir only required approximately 1 minute with normal over
head.
The file arrived intact and Mike was able to open and see the JPG image.

Phase 2 of the plan to test 9600 baud and larger files was never tested.
We will try to fit this test in for Mir in February 2000

73 Miles WF1F MAREX-NA














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