[NTLK] compiling source

I am a returning Newton user (--I knew a lot 10 years ago that I have
forgotten). I am trying to resurrect a program I used to use, but the
files I have are mostly .txt, .lyt, and .dat files rather than .pkg.
I *know* to use Toolkit, but it will not run in Classic (beige tower)
-- unkown error, and will not open files (any files!) in Native
(5500) -- disk error.
Any suggestions?

-- 
This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries
Official Newton FAQ: http://www.chuma.org/newton/faq/
WikiWikiNewt for all kinds of articles: http://tools.unna.org/wikiwikinewt/