Good point....I used to keep a whole stick of UART chips here to replace
blown units - back when my private company provided dial-up Internet access.
----- Original Message -----
From: "Peter Frenning [OZ1PIF]" <peter@frenning.dk>
To: <k2xx@swva.net>; "Discussion of Ten-Tec Equipment"
<tentec@contesting.com>
Sent: Monday, March 02, 2009 10:41 AM
Subject: Re: [TenTec] FW Update Problem w/O2
> Joe Giacobello skrev:
> > Jim and Billy, thanks for your inputs, but I'm continuing to have both
an exasperating and mysterious series of problems with the FW installation.
> >
> > Apparently, those messages that I was receiving on the Orion screen were
indicative of the FW code being loaded albeit at a very slow pace. I went
back and tried it again several times and on some occasions the transfer
would stop at an early line and the update software would close. The
furthest I got before the transfer stopped was program flash 266. The speed
seemed to be erratic, but it was generally quite slow. It made little
difference whether I used hardware flow control or none and 57.6K speed or
slower. Even though I usually received the error message that there was no
communication between update software and the Orion, the Orion display
showed
> Snip snip snip
>
> Dear Joe et al,
>
> What you need to realize is, that we are using communication at its most
> basic level here. Asynchronous communication (and RS232C) was invented
> long before the advent of micro processsors, and was designed for (in
> today's eyes) very primitive hard-wired logic. What's called "Handshake"
> is barely that, it's more like waving a flag and hoping your partner
> sees it.
>
> Even today, the standards of those days applies, whether we use DOS or
> Windows, Linux or Unix, or various other systems the drivers (the SW our
> applications "talk" to when wanting to transmit or receive data) all
> behave in a "send and forget" way or, on the receive side "wait forever"
> mode. This is clearly not very conducive so a "time-out" mechanism has
> been built into the driver: When the sender has presented the data (a
> character) to the transport medium, it'll wait for a while for proper
> signaling, before letting the application know thet it's ready for the
> next character, if nothing happens, it'll clear its status and signal
> that it's ready for the next anyway! Thus the sending application may
> think that, although things are progressing at a snails pace, everything
> is going well. Likewise on the receiving side: if nothing happens for a
> while after signaling readiness for the next character it'll send a
> "NULL" character upstream, reset itself and signal readiness for the
> next character, and so on ad nauseam. Again the receiving application
> will get a string of absolutely useless "NULLS" very slowly, but since
> it doesn't know what it's supposed to receive, never realize that
> anything is amiss.
>
> This is exactly what you are seeing!
>
> To sum it up: when using asynchronous serial communication, if what you
> see is very slow (orders of magnitude) progress, it's a clear indicator
> that the basic connection hasn't been made correctly!!!! Most likely
> your cable, but possibly blown RS232C chips at either end (happens very
> often - they are fragile beasts).
> An easy way of testing you interface is to establish connection with a
> Rig Control program like "Ham Radio Deluxe" or any other program that
> suits you. If that works you are all set - the Flash process will also
> work, if not find and fix you basic communication problem.
>
> BTW: the most common way to blow an RS232C interface is to hot-plug a
> cable between two devices, especially if neither has a good common
> ground connection.
>
> --
> Vy 73 de OZ1PIF/5Q2M, Peter
>
> ** CW: Who? Me? You must be joking!! **
> email: peter(no-spam-filler)@frenning.dk
> http://www.frenning.dk/oz1pif.htm
> Ph. +45 4619 3239
> Snailmail:
> Peter Frenning
> Ternevej 23
> DK-4130 Viby Sj.
> Denmark
> ***********************************
>
>
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