C - enable control via break key.

Description:

This command may be used to re-enable use of the break key for initiating manual breakpoints and/or terminating output being produced by subsequent commands. Normally, the user will not have to exercise this command; i.e., break control is automatically enabled by the trace package when

the package is first entered,
any subsequent use of the break key is made,
a breakpoint is executed,
and a callss command has been completed.

Thus, its use is limited to cases where the target program has altered the break vector in the slave prefix area.