( compiled )
    BP INCx, BP INCx, [BP] 0 DX MOV[]+x, ( pushRS )
    DX DI MOVxx, DX INCx, DX INCx, ( --> IP )
    DI [DI] MOVx[],
    JMPs, lblexec @ RPCs,

lblchkPS BSET ( CX -> expected size )
    AX PS_ADDR MOVxI, AX SP SUBxx, 2 SUBAXI, ( CALL adjust )
    AX CX SUBxx,
    IFNC, ( we're good ) RETn, THEN,
    ( underflow ) DI 0x06 MOVxm, JMPs, lblexec @ RPCs,