The MediaWiki bits are documented here.
You use the Wiki tag <source lang="..."> to enable syntax highlighting, then use </source> when finished. If you forget the lang parameter or make a mess, you'll visually (at Preview/Save time) get an error. There are other parameters that you can specify too; please see the above MediaWiki link. You can also use <syntaxhighlight> as an alternate tag if you want, but I find <source> to be more convenient.
The highlighter supports many languages (see attachment for the official list that's on the server), but most relevant is the fact that it supports 3 different types of 6502 models:
- 6502acme -- MOS 6502 (6510) ACME Cross Assembler format
- 6502kickass -- MOS 6502 (6510) Kick Assembler format
- 6502tasm -- MOS 6502 (6510) TASM/64TASS 1.46 Assembler format
You do not need to <pre> or space-indent your code to use this (I imagine many will find that useful); you can still do all that if you want of course.
I went through most of the Wiki pages (searching for opcodes like bpl, bmi, and rts) and edited them to use <source lang="6502tasm">. I'm sure I missed some, obviously, but my wrists/fingers were getting sore. Here's an example:
http://wiki.nesdev.com/w/index.php/VRC7 ... rite_Delay
I'll state up front that the colour scheme for 6502tasm is not exactly what I'd like (ex. the extreme light-grey for comments is hard for me to read,). There are ways to modify the colours used in the CSS for the highlighter for those languages (within MediaWiki itself), so if we all come up with recommended improvements (please learn how to use things like Tools/Web Developer/Style Editor in Firefox, and/or Firebug for Firefox!) and want to make our own "theme" for the source code, that's great. I'm always open to suggestions. Upload screenshots of what looks good to you, with the ideal CSS changes, and any of us who are Wiki admins can put them into place.
Changing the syntax highlighter language itself (ex. "make address labels named PPUADDR bold and black") is something I would rather stay away from -- the reason is that if we upgrade MediaWiki (and especially the extension itself), it's extremely likely we'd lost those changes (meaning we have to start keeping a patch repository and so on -- we used to do this, and it's difficult to manage). However, if someone did make a new language called (for example) nesdev that was specific to all our needs (and was NES-specific), I'd be willing to make an exception and deal with keeping track of that one-off.
Hope this helps or at least gets people editing. :-)
Footnote: warning to those poking about: avoid looking at "Recent changes". I spent almost 3 hours (I think?) messing about with unrelated things (mainly MediaWiki templates) which failed miserably, so you'll see all sorts of template-related things in there, followed by a bunch of template deletes. I did get a couple templates working like {{sub}} and {{sup}} though (for sub- and superscript -- see MediaWiki's Template page on those for how to use them), so my efforts there weren't a total failure. Templates in MediaWiki are such a pain in the ass. I think I spent the past 4 hours just on the wiki. Gruhhh...