( TODO: move these words with other native words. )
H@ 4 + XCURRENT ! ( make next CODE have 0 prev field )
CODE (br) L1 BSET ( used in ?br )
PC 0x3f - ORG @ 0x3d + ! ( stable abi )
    DI DX MOVxx, DI [DI] MOVx[], DX DI ADDxx,
;CODE
CODE (?br)
PC 0x43 - ORG @ 0x41 + ! ( stable abi )
    AX POPx, AX AX ORxx, JZ, L1 @ RPCs, ( False, branch )
    ( True, skip next 2 bytes and don't branch )
    DX INCx, DX INCx,
;CODE