On Sun, 3 May 2020 at 12:14, Clem Cole <clemc@ccc.com> wrote:

Paul W -- do you remember if DEC TLG did a version of dbx for Ultrix (Leslie might remember)?  FWIW: I know that DEC had a number of different debugger projects so on the UNIX side over the years, and I really don't remember what was done for the VAX, as I was not there at the time.  By MIPS/Alpha in the mid-late 90's there was a whole new debugger stream that had been developed at part of GEM, but there was another one that came from MIPs too which was based on dbx.

Perhaps unsurprisingly, as Ultrix 1 was basically just 4.2BSD with some tweaks/addons, dbx has been there since the beginning as /usr/ucb/dbx.  The binary in 1.1 has SCCS strings mostly dating it to '83 and the 2.0 source tree has dates that are mostly December '84.