: mode! ( c -- ) 4 col- 0 AT-XY ;
: contents
    16 0 DO
        large? IF 3 ELSE 0 THEN I 3 + AT-XY
        64 I * BLK( + ( lineaddr ) xoff @ + DUP width + SWAP
        DO I C@ 0x20 MAX EMIT LOOP LOOP
    large? IF 3 16 gutter THEN ;
: selblk BLK> @ PREVBLK ! BLK@ contents ;
: pos! ( newpos -- ) EDPOS @ PREVPOS !
    DUP 0< IF DROP 0 THEN 1023 MIN EDPOS ! ;
: xoff? pos@ DROP ( x )
    xoff @ ?DUP IF < IF 0 xoff ! contents THEN ELSE
        width >= IF 64 COLS - xoff ! contents THEN THEN ;
: setpos ( -- ) pos@ 3 + ( header ) SWAP ( y x ) xoff @ -
    large? IF 3 + ( gutter ) THEN SWAP AT-XY ;
: cmv ( n -- , char movement ) acc@ * EDPOS @ + pos! ;