CODE /MOD 2 chkPS,
    BX POPx, AX POPx, DX PUSHx, ( protect )
    DX DX XORxx, BX DIVx,
    BX DX MOVxx, DX POPx, ( unprotect )
    BX PUSHx, ( modulo ) AX PUSHx, ( division )
;CODE
CODE ! 2 chkPS, DI POPx, AX POPx, [DI] AX MOV[]x, ;CODE
CODE @ 1 chkPS, DI POPx, AX [DI] MOVx[], AX PUSHx, ;CODE
CODE C! 2 chkPS, DI POPx, AX POPx, [DI] AX MOV[]r, ;CODE
CODE C@ 1 chkPS,
    DI POPx, AH AH XORrr, AL [DI] MOVr[], AX PUSHx, ;CODE
CODE I [BP] 0 PUSH[w]+, ;CODE
CODE I' [BP] -2 PUSH[w]+, ;CODE
CODE J [BP] -4 PUSH[w]+, ;CODE
CODE (resSP) SP PS_ADDR MOVxI, ;CODE
CODE (resRS) BP RS_ADDR MOVxI, ;CODE