DEBUG - system rpl debugger
                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~

SDBG    ( ob --> )
        Starts system rpl debugger with the program on stk1
        (Or ID/LAM/ROMPTR)
->SST
        Single steps one instruction.
->IN
        Single steps one instruction. Secondaries/romptrs/ids/lams are
        stepped into if they contain a program.
SNXT
        Displays next commands.
        Second press displays return stack contents.
SST->
        Single steps in slow-mo. Second press starts fast-mo in which stack
        display is not updated.
IN->
        Similar to above with ->IN.
DHALT
        Similar to HALT, but exits similarly to other debugger commands.
        (4/5/7 is executed if it is found to exist)
DBRK    ( ob --> )
        Sets breakpoint command. SST-> and IN-> are stopped if ob was
        executed.
DEXEC   ( ob --> )
        Executes stk1 on top of debugged program.
        Execution is done by adding COLA DHALT commands to stk1 and evaluating
        it on top of the debugged body that is on the return stack.

        With this you can make your own debugger commands but be careful not
        to use return stack levels below the program, you could mix up the
        original UI that is returned to after finished the debugger.

        Example commands:

        Skip next command:                      :: ' :: RSKIP ; DEXEC ;
        Drop current stream:                    :: ' RDROP DEXEC ;

        (The difference is due to the fact that RSKIP already is a secondary.)

        Drop return stack:                      :: ' :: RSWAP RDROP ; DEXEC ;
        Recall current stream:                  :: ' :: R@ ; DEXEC ;

        Setting new PC: (hxs --> )
                        :: CK1&Dispatch ELEVEN
                                :: HXS># #5- PTR C612 (RclData)
                                   ' :: RDROP >R ;
                                   DEXEC
                                ;
                        ;

LOOPS
        Displays data in loop environments. Use up/down arrows to scroll
        through the environments.
LAMS
        Not implemented yet.
IN?
        Toggles debugging into secondaries (to avoid unnecessary debugging of
        subroutines when using IN). Does not affect IN for IDs/LAMs/ROMPTRs .

Notes about HP commands:

        CONT works normally.
        KILL does not destroy error traps nor loop environments. :(
        To use HALT (or DHALT) start SDBG first, then press CONT.