Update or remove some dead links

www/index.html

@@ -527,18 +527,15 @@ Example use:
 <h3>VxWorks Links</h3>
 
 <p>Check out the <a
-href="http://www.bluedonkey.org/cgi-bin/twiki/bin/view/Books/VxWorksCookBook">VxWorks
-Cookbook</a> at John Gordon's site, <a
-href="http://www.bluedonkey.org/">bluedonkey.org</a>.  It's an
+href="https://web.archive.org/web/20070220163544/http://www.bluedonkey.org/cgi-bin/twiki/bin/view/Books/VxWorksCookBook">VxWorks
+Cookbook</a> at John Gordon's site, bluedonkey.org.  It's an
 excellent collection of VxWorks (and related) embedded technique
 assembled by one of the masters.</p>
 
 <h3>Scheme Links</h3>
 
 <ul>
-<li><a href=
-"http://www.swiss.ai.mit.edu/projects/scheme/index.html">The MIT
-Scheme Homepage</a><br>
+<li><a href="//mit.scheme.org/">The MIT Scheme Homepage</a><br>
 <p class="item"><i>The MIT Scheme interpretation compiles directly
 to x86 machine code, and is consequently very fast, and has an
 integrated debugger and graphics support. Very professional. Runs
@@ -567,7 +564,7 @@ this research:</p>
 <ul>
 <li>
 <p class="item">Benjamin S. Skrainka (Contact him if you need
-<a href="http://www.skrainka.biz">VxWorks training</a>!)</p>
+VxWorks training!)</p>
 </li>
 
 <li>
@@ -578,13 +575,11 @@ extraordinaire</a>)</p>
 
 <li>
 <p class="item">Brendan Smith (Computer trouble in the Skagit
-Valley? <a href="http://www.brendan-smith.net">Give him a
-call!</a>)</p>
+Valley? Give him a call!)</p>
 </li>
 
 <li>
-<p class="item">...and my lovely wife
-<a href="http://www.juliebird.net/">Julia</a>, who often wondered what
+<p class="item">...and my lovely wife Julia, who often wondered what
 the point of having a computer day job was if I was just going to
 spend the rest of my time hacking in the garage.</p> </li> </ul>