USE - user automatic commands for trace package.

Syntax:

USE <nnnn> <input-string>

Description:

This command first moves <input-string> to an internal buffer. Whenever the trace package is about to execute an instruction which falls into the set of those being traced, it will first TSX1 to <nnnn> with index register 3 pointing to the IC&I and index register 4 pointing to the registers. The user supplied routine can do whatever it wants but must return to TRACE via '0,1', '1,1' '2,1', or '3,1'. Depending on which return was taken, the trace package will do one of four things:

0,1 -- Do nothing (execute the instruction)
1,1 -- Execute <input-string> as a command
       and then execute the instruction.
2,1 -- Execute <input-string> as a command
       and then pause.
3,1 -- Pause.

In this manner, the user can build up a routine which tests for certain (arbitrary) conditions being present in his control structures and have the full command facility of trace available to him if the routine determines that this is necessary. Also, if the situation is sufficiently critical, it can give control back to the user.

Notes:

PAUSE mode must be turned off (NOPAUSE), in order for the USE code to be invoked.