Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!bu-cs!dartvax!eleazar.dartmouth.edu!jskuskin
From: jskuskin@eleazar.dartmouth.edu (Jeffrey Kuskin)
Newsgroups: comp.sys.mac.programmer
Subject: Disassembler info needed
Message-ID: <15994@dartvax.Dartmouth.EDU>
Date: 9 Oct 89 01:51:15 GMT
Sender: news@dartvax.Dartmouth.EDU
Reply-To: jskuskin@eleazar.dartmouth.edu (Jeffrey Kuskin)
Organization: Dartmouth College, Hanover, NH
Lines: 24

I admit to ignorance in the following area, so please
bear with me.

I need to write a disassembler for the Mac (the 68000
only, to be specific).  Could someone point me in the
right direction in terms of how to decode the opcodes.

I understand the decoding process (extension words,
addressing modes, etc.), but am unsure how to
efficiently read an instruction stream and generate
the proper mnemonics.  Do I just grap the next opcode,
decode it bit by bit (or in groups of 3 or 4 bits) and
then, once I have the instruction determined, read the
necessary extension word(s)?  Or is it possible to use
some sort of hashing function to get the instruction
type?

Advice and/or code would be appreciated.

Thanks.

-- Jeff Kuskin, Dartmouth College

E-Mail:  jskuskin@eleazar.dartmouth.edu