Subject:
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Re: remote control and rcx -- Download Failures
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Newsgroups:
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lugnet.robotics.rcx
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Date:
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Tue, 13 May 2003 01:08:03 GMT
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Reply-To:
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Dick Swan <dickswa@sbcglobal.[avoidspam]net>
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Viewed:
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3158 times
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Several people report download failures at about 75% of way through
downloading the 2.0 firmware. This problem could be related to using
one of the "quad" speed downloading routines available in many of the
alternative development systems. The following explanation (extracted
from a Dec 09/2002 11:29 PM post) explains why this frequently occurs
at 75% completion.
"Standard Lego software uses 2400 baud data rate and a protocol that
sends "double" bytes. The "double" byte is that each data byte is
followed by its complement. Alternative development systems use a quad
speed downloader that operates at 4800 baud and eliminates the
complement data bytes.
Message transmission in quad speed is not reliable when there is a
large block of consecutive zeros in the message data. I have found
that it is not robust when more than 25+ consecutive zeros are
transmitted.
Unfortunately the 2.0 firmware (i.e. 0328) has a couple of large
blocks of consecutive zero bytes at about 73-80% and 88-90% of the
downloading.
One solution is to disable the quad speed downloader.
Fiddling the wires to the serial cable re-arranges the orientation of
the IR tower and RCX and may allow the downloading to work. It's not
the serial cable that is bad.
"Lars Gjerløw Jørgensen" <lgjPURGE@jyde.dk> wrote in message
news:Xns9376C8BF77E5Algjatjydedotdk@209.68.63.236...
> Brian B. Alano's utterance expressed in news:HEMMAJ.1n01@lugnet.com:
>
> > I had a similar experience. In fact, it happens to me fairly
> > regularly. I believe I've traced it to bad connections in the • tower's
> > serial cable. After I fiddle with it the problem usually goes • away.
>
> I have tried fiddling with the wires, but it's the same thing.
> At about 75% through the firmware download, it stops :(
>
> --
> | lars gjerløw jørgensen | lgj[at]jyde[dot]dk |
> | N55 43.184 E12 32.405 | www.lgj.dk | oz2lgj |
> Mark Hamill:"I have a sneaking suspicion that if there were
> a way to make movies without actors, George (Lucas) would do it."
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Message has 1 Reply:
Message is in Reply To:
 | | Re: remote control and rcx
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| Brian B. Alano's utterance expressed in news:HEMMAJ.1n01@lugnet.com: (...) I have tried fiddling with the wires, but it's the same thing. At about 75% through the firmware download, it stops :( (21 years ago, 9-May-03, to lugnet.robotics.rcx)
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