added error alerts; fixed window list; fixed z80 stack; astrocade .c bios

tools/fontgen/index.html

@@ -35,7 +35,7 @@ if (window.location.host.endsWith('8bitworkshop.com')) {
       <li>Select a font below (check out the search and filter options.)</li>
       <li>Choose a platform from the Presets menu, or choose your own encoding options.</li>
       <li>Select a range of characters to encode.</li>
-      <li>Check out the preview bitmap to make sure none of your characters are visibly cut off, or increase your height/width (if your platform supports it.)</li>
+      <li>If you have out-of-range errors you want to fix, adjust the Y Offset value, or increase your height/width (if your platform supports it.)</li>
       <li>Copy the output to the clipboard.</li>
       <li>Paste it into your code.</li>
     </ol>