Retro1.org codex

HO                                                        CMS Immediate command

Use the HO (Halt tracing) Immediate command during the execution of a command
or one of your programs to stop the recording of trace information.  Program
execution continues to its normal completion, and all recorded trace
information is spooled to the printer.  The format of the HO command is:
+----------+------------------------------------------------------------------+
| HO       |                                                                  |
+----------+------------------------------------------------------------------+

You can issue an Immediate command only after causing an attention interrupt by
pressing the Attention key (or its equivalent).  The command is processed as
soon as it is entered.  It is also executed immediately when stacked in an EXEC
procedure.  Any program execution in progress is suspended until the Immediate
command is processed.