I finally got ITS running on my simh plan9 port. I discovered that one of the DDT command from ITS is snarf
:SNARF <job> if the current job (say, FOO) has an inferior named <job>, this command takes <job> away from FOO and then does ":JOB <job> ". Thus, <job> becomes a direct inferior of the DDT executing this command, instead of an indirect inferior. FOO is not told that its inferior is gone, but if it is a DDT it will recover after an $J is done to it. This command is most useful when done to a HACTRO that got detached because of a top- level interrupt, but whose inferiors are valuable. (The thing to do is "HACTRO$J :SNARF TECO ", etc.)