Hello Goerge!
I remember a Routine that looks like the
routine you´ve Posted. After removing that
" Do / Undo " Routine the System crached,
because the timing was in trouble..

Your Routine looks like the code I´ve tried
to understand about a Year ago ..



CLR EA ;* ... do
INC P2 ;* ... do
MOVX A,@R1 ;*
DEC P2 ;* ... undo
SETB EA ;* ... undo

what does your CPU / System, If you remove
the Code below ?


Cheers,
Stefan