From: Henry Bent
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? Was there a way to easily produce a full disassembly?
'adb' is quite late. We had it on the PWB1 (V6 enhanced, basically) system at
MIT, so its roots lie before V7. (Every time I run across people who think V7
is early, I go into 'get off my lawn' mode.)
The first thing I know of that could disassemble PDP-11 code on Unix was 'db',
which dates back to V1:
https://minnie.tuhs.org//cgi-bin/utree.pl?file=V1/man/man1/db.1
It wasn't optimal for doing disassembly, because it was non-trivial to
dump an entire object file as assembler source - but it could be done.
Later (V5 era) there was something called 'cdb', which was 'db' with
extensions to make it useful for debugging code whose source was in C:
https://minnie.tuhs.org//cgi-bin/utree.pl?file=V4/man/man1/cdb.1
There were other non-Unix disassembler (such as DDT), also.
Noel