[TUHS] Disassemblers

Noel Chiappa jnc at mercury.lcs.mit.edu
Sun Jun 20 03:57:59 AEST 2021


    > 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


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