( user-facing lines are 1-based )
: T 1- DUP 64 * EDPOS ! _pln ;
: P _type EDBUF EDPOS @ _cpos 64 MOVE BLK!! ;
: _mvln+ ( ln -- move ln 1 line further )
    DUP 14 > IF DROP EXIT THEN
    _lpos DUP 64 + 64 MOVE
;