Re: WWW, Mosiac, and Access for People with Disabilities

Tony Sanders (
Fri, 7 Oct 1994 23:06:29 +0100

Chris, I hope you don't mind me posting this back to the list but I think
it's important to get this information out and make this clearer in the
HTML/HTTP documentation.

The documentation on ISMAP should be clarified but it's not obvious to me
where all this should go (there currently doesn't seem to be anywhere that
describes how HTML features map onto the URL).

In summary:
A request to a URL with the ISMAP or SPACEJUMP attribute should
either contain a standard query with the relevant index coordinates
(from mouse selection or other) or it should not contain a query
at all, in which case the server should generate a reply assuming
that the client doesn't have the capability to index in the required
manor (generally the server will return an HTML document with a
list of the choices).

Chris Lilley, Computer Graphics Unit writes:
> > Just so you know, ISMAP is designed so that a server can generate a text
> > menu for the image if the client asks for it
> Is that can in theory, or does in practice?
Plexus does this in practice. In the imagemap file you can either specify
a menu description string (and have a menu generated on-the-fly) or you
can specify a default document. I believe that most active images served
by Plexus servers use one of these methods.

Here is the orig prototype:
The decoding URL is:
If you request that URL without a query then you will get a menu.

All it took to set this up was this in the map file:
decode-walk default server/walk/default.html

> Certainly the NCSA server does not seem to behave like this.
Then it should be fixed (patches have already been posted).

There is no reason that text-only clients should not be able to
fully operate in the WWW environment while still allowing full
experimentation with graphical navigation.