shop here first
http://ti89.acz.org/references.htm
the tutorials are a bit calculator biased,
but you fill fish alot of generic info.
If you suspect to that your assembler is non-
standard, then pay a close attention to the
official doc http://ti89.acz.org/archive/68kpm.zip
There are many different syntaxes for the 68K
, so make sure you don't get confused by that.
There are plenty of palm emulators out there,
if you want to test your code on a PC, get
any of them. For a generic MC68000 emulator,
go to the "emulators" section in the above
mentioned page, and get the DOS based one,
right in the bottom of the page. It is a pure
68K environment, with minor console I/O
facility, no big library or system calls,
just enough to test the algos.
Hmmm, reversing; does the name "palmdeMON"
ring a bell?

Go to carp's site and get the goodies.
http://carpathia.cjb.net
What else? yeah, tsehp's germinating mirror
is always full good stuff; there is an old
paper IIRC about palm, and there might be
newer ones.