Anybody good at disassembly????

From: Jerome Fine <>
Date: Thu Jun 28 17:21:59 2001

>Curt Vendel wrote:

> There are tons of disassemblers available for current moderm PIC MCU's, the
> most popular being the PIC1684.
> >Gene Ehrich wrote:
> > I remember back in the early days at IBM right before the 360 was announced
> > that they were talking in the industry of the possibility of a
> > disassembler. Most people poo-poo'd it as impossible. Datamation magazine
> > had a cartoon with a picture of a machine labeled disassembler with a
> > conveyer belt on each side. A worker was feeding cans of applesauce into
> > the machine and on the other side apples were coming out.

Jerome Fine replies:

I realize this will not help your specific problem, but I want to add that there
are two basic types of disassembler:
(a) Those that start from the final executable file - probably the majority
(b) Those that start from the OBJ file.

For the PDP-11, about the best program that I use is DECODE with a few
enhancements - the most important being the ability to allow an odd address
label in the case of an .Ascii text definition. Also helpful for RT-11 users
is a comment inserted when an expansion for an EMT macro like .LookUp
is found or .ReadF or many others. There is also the start of some code
to handle overlays, but not complete.

DISSAV is also available.

For the second type (b), there is UNMAC which also has some enhancements
that allow UNMAC to be applied to itself. Specifically, even though the original
source is in FORTRAN 77, the OBJ files can be put through UNMAC to produce
a *.MAC file that can be assembled via MACRO to produce a slightly different
OBJ file but which then LINKs to produce a final SAV file that is identical to the
original UNMAC.SAV file produced from the OBJ files that were produced by
the FORTRAN 77 compiler in the first place. Note that the original UNMAC
could not do that without substantial intervention by hand if at all.

By the way, while I realize that most members of this list are focused toward
hardware, the few of us who like software do not seem to mention it very
much, as if software is not important. Perhaps those of you who are the
hardware type could explain to me why the software holds so little interest.

While I agree that the hardware is needed to run the software (well not
actually anymore in the case of a PDP-11), I have never seen anything
useful from a system that has dumb software. But why does someone
feel that the solution is complete when the hardware is working?

Sincerely yours,

Jerome Fine
Received on Thu Jun 28 2001 - 17:21:59 BST

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