[TUHS] Disassemblers

[Clem Cole]

On Sat, Jun 19, 2021 at 11:05 AM Henry Bent <henry.r.bent at gmail.com> wrote:

> From what I can gather the only way to reasonably examine the disassembly
> of a program in the early days of Unix was adb.  Is this true?
>
>From Research, yes - although sdb and later dbx could do it also I think.



> Was there a way to easily produce a full disassembly?
>
Yes, look at the contents in the early USENIX (Harvard) tape.  IIRC: Along
with the macro-11 assembler and linker, there was also a disassembler -- I
want to say it was done at Cooper Union, but it may have been
someone else[The CU folks got the DEC PDP-10 BLISS binary to run on an
emulator 'good enough' on their 11/45 to they could 'port' the DEC Fortran
compiler to V6.  They used/built up PDP-11 tools to support that project].

BTW: there was a version of the DEC DDT that was on those early tapes too
that somebody wrote.   I started with DDT on V6 because I was coming over
from the DEC OS world of PDP-10's and RT-11 and adb did not yet exist.
 But IIRC it was fragile, had issues when V7 came out, so I just taught
myself adb when it appeared.

There was an even better set of assembly/disassembly/link tools  from
'down-under' on ??maybe? the Delaware tape.  Plus, Purdue released a ton of
microprocessor tools, which included PDP-11 support.  All of them tried to
use the symbol table to reconstruct things like jsr's and memory access.
Somebody [IIRC it was Phil Karn but I don't remember] tried to do some
instruction pattern matching / early AI stuff, to see if they
could reconstruct some of the code with some human help.  As I recall he
could pick up pointers and if given some header files for sizes would try
to match code snippets, but I have no idea how he got or what happened too
it.



> I'll confess to being fairly ignorant of adb use since I always had dbx or
> the equivalent available.
>
ᐧ
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