Make XTK work (sort of).

* Switch to atmega48P. No need for an atmega8 here.
* Fix the XT keyboard protocol generation. It's fairly simple once understood.
* Fix (mostly) the scancode conversion table

Things are rather glitchy, still. Since the XT protocol is not time critical at
all, this points to either:
* Problems in the PS/2 scanning code
* Errors in the scancode map


git-svn-id: svn://pulkomandy.tk/avrstuff@101 c6672c3c-f6b6-47f9-9001-1fd6b12fecbe
3 files changed