*REM PDP-11 Extended Instructions
$MACRO MUL
&P0    MPY  &P1,&P2
$END
$MACRO ASH
$REM supports 16-bit, not 32bit
$REM moves &p2 into R0
$REM don't specify R0 in instruction!
&P0    MOV  &P2,R0
       SRC  &P1,R0
$REM no left shift
$END
*ASHC