Subject:
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Re: rcxhttpd?
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Newsgroups:
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lugnet.robotics.rcx
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Date:
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Thu, 22 Jul 1999 01:43:22 GMT
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Viewed:
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1425 times
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You could use a terminal server and at leaset telnet to the rcx.
KL
Robert Munafo wrote:
>
> In lugnet.robotics.rcx, Todd Lehman writes:
> > [...] a scaled-down version of httpd actually running on the RCX brick
> > itself. Obviously, it couldn't hold very many static pages, and it
> > would need a dedicated IR link to a host machine, but I wonder what
> > sorts of things could be done? Anything useful? [...]
>
> Since the RCX has essentially a serial interface to the outside world, you
> would need to encode and decode the HTTP requests and responses into a
> serial-based protocol. If you actually wanted the RCX to be plug-and-play
> compatible with existing TCP/IP communications devices (like your PC acting as
> a firewall) then you would have to use an existing protocol for IP over serial
> line, like SLIP or PPP. That means you're implementing four layers of protocol:
> SLIP or PPP, IP, TCP and HTTP. Even a minimal subset of each of these protocols
> adds up to a fair amount of code. I don't know how much memory the code would
> take but it's probably pushing the 32K limit.
>
> However, the minimal implementation of HTTP [1] is designed to operate over any
> type of connection, not just a TCP connection. In other words, you can forego
> the SLIP/PPP, IP, and TCP layers of the protocol and run HTTP directly over a
> serial line. If you do this, HTTP is extremely simple. A request consists of
> sending "GET " followed by the desired URL and a CRLF; and the response
> consists of the ASCII text being sent back followed by "closing of the
> connection". To signal "closing the connection" you would probably send a null
> character (ASCII 0) or a control-D (ASCII 4).
>
> This approach, of course, has side effects:
>
> - The computer on the "other end" of the serial line has to know that it's
> doing HTTP directly over serial. You'd probably have to write special software
> to do this.
>
> - No error checking or retry to handle noise in the line (which would come
> mainly from the infrared link, not from the serial cable itself)
>
> - No ability to run other protocols over the same link (like FINGER as
> someone else suggested)
>
> - Robert Munafo
>
> 1. http://www.w3.org/Protocols/HTTP/AsImplemented.html
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Message is in Reply To:
 | | Re: rcxhttpd?
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| (...) Since the RCX has essentially a serial interface to the outside world, you would need to encode and decode the HTTP requests and responses into a serial-based protocol. If you actually wanted the RCX to be plug-and-play compatible with (...) (25 years ago, 19-Jul-99, to lugnet.robotics.rcx)
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