:asm textmode
  MOV AX 0x03 #
  INT 0x10 #
  NEXT

0 var, textpageid
0 var, textpage

: page! dup textpageid ! 12 << textpage ! ;

:asm showpage
  POP AX
  MOV AH 0x05 #
  INT 0x10 #
  NEXT

:asm movecursor ( xy -- )
  MOV BH textpageid @+
  MOV AH 0x02 #
  POP DX
  INT 0x10 #
  NEXT

:asm cursorshape! ( shape -- )
  POP CX
  MOV AH 0x01 #
  INT 0x10 #
  NEXT

: hidecursor 0x2607 cursorshape! ;
: showcursor 0x0607 cursorshape! ;

0x0f var, textpen

 0 const black  1 const blue      2 const green   3 const cyan
 4 const red    5 const magenta   6 const brown   7 const lgray
 8 const gray   9 const lblue    10 const lgreen 11 const lcyan
12 const lred  13 const lmagenta 14 const yellow 15 const white

: fg! textpen @ 0xf0 & | textpen ! ;
: bg! 4 << textpen @ 0x0f & | textpen ! ;

80 const pagew
25 const pageh

0xb800 const TEXTMEM

} : PREP-TEXTCOPY
  MOV ES t& TEXTMEM @+
  MOV AH textpen @+
  MOV DI textpage @+ ; {

:asm fill-page ( char -- )
  INT 3 #
  POP AX
  PREP-TEXTCOPY
  MOV CX pagew pageh * #
  REPZ STOSW
  NEXT

0 var, textpos
: textx textpos @ 1 >> pagew % ;
: texty textpos @ 1 >> pagew / ;
: textx! 1 << texty pagew 1 << * + textpos ! ;
: texty! pagew 1 << * textx 1 << + textpos ! ;
: nextline texty 1+ pagew 1 << * textpos ! ;

} : PREP-TEXTCOPY-XY
    PREP-TEXTCOPY
    ADD DI textpos @+ ; {

:asm draw-text ( s -- )
  MOV BX SI
  POP SI
  PREP-TEXTCOPY-XY
0 :>
  LODSB
  OR AL AL
  JZ 0 @>
  STOSW
  JMP 0 <@
0 <:
  SUB DI textpage @+
  MOV textpos @+ DI
  MOV SI BX
  NEXT