[comp.sys.m68k] code compression

rl@cbnewsl.ATT.COM (roger.h.levy) (02/10/90)

A multi-processor system I am involved with will be required to download
code updates from a primary processing board to satellite boards.  The
primary board will store code in prom for all boards and it will be the
only board replaced when updates are released.  The satellite boards
will receive the updates and store them in flash-eprom.

To save prom space and minimize out-of-service time due to downloading,
I'd like to compress the 68000 code that the primary board stores for
the satellites.  Is there a compression algorithm that has been found
to be particularly suited to this purpose?  Ideally, I'm after 2:1 (or
better) compression but I don't want to spend a lot resources (e.g.
ram, rom, time) on uncompressing.  I don't care how complex the compre-
ssion algorithm is since my target won't do that.  I've found that a 16
bit LZW algorithm can achieve 2:1 compression but it doesn't meet my
other criteria.  Any pointers, especially to source code, would be
appreciated.

Roger Levy
...!att!groucho!rl