I don't know of any system where you can *not* tell the
serial line to handle binary data, even if it might not be
the "standard" setting.

The problem isn't the RS232 link as such, it's the higher
level "terminal driver" in the OS. Think of *real*
operating systems such as VMS :-)

I do not think this is a problem, on the planned
plattforms (neither on VMS for that matter...).

I still *do* think that communication debugging with
a serial line listener is easier with "plain text"
messages (but not impossible).


Jan-Erik.

PS.
And of course, even the "data" part would have to be sent
in HEX or whatever to avoid control chars...
DS.





-----Original Message-----
From: Olin Lathrop [mailto:olin_piclist@EMBEDINC.COM]
Sent: den 2 juni 2003 16:34
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: [PIC]: FREE PIC programmer


> I took a quick look at the EeasyProg(tm) protocol.
> http://www.embedinc.com/easyprog/easyprog_prot.txt.htm
>
> I see that it uses an "opcode byte" with values (dec)
> 1 - 38 (currently). Now, some of these values, such
> as 10 (LF) and 13 (CR) may create problems on
> platforms where a standard serial port used some
> kind of "terminal driver". Depending on how the port
> is setup ("passthrough", "binary" or whatever) these
> control characters might create some problems.

I've never run into a system that couldn't handle straight binary bytes
over RS-232.  Besides, even if the opcodes avoided "control characters",
it would be a great deal of trouble to avoid them with the data bytes.
So, once you buy into using a binary protocol, you might as well make
things easy and start the opcodes at 1 or 0.

> Personaly, I don't think it wise to use the lower
> 32 ASCII chars as something else then what they once
> was defined for.

Probably wise, but this protocol isn't ASCII.

Do you know of a particular system that can't do raw binary I/O over its
serial port?


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