org     100h

EntryPoint:
        mov     DX, 320 * 129 + 220
        mov     AH, 0Fh
        int     10h


        mov     [bOldMode], AL
        mov     [bOldPage], BH

        ; Включение 13-го видеорежима [320x200, 256 цветов]
        mov     AX, $0013
        int     10h

        ;
        push    $A000
        pop     ES

StartDraw:
        ; Небо
        mov     AL, 11
        xor     DI, DI
        mov     CX, 320 * 160
        rep     stosb

        ; Вода
        mov     AL, 1
        mov     DI, 320 * 160
        mov     CX, 320 * 40
        rep     stosb


        ; Лодка
        mov     AL, 114
        mov     DI, DX
        mov     CX, 120
        mov     BX, 0

.Boat:
        add     DI, 201
        add     DI, BX
        sub     CX, 2
        push    CX
        rep     stosb
        pop     CX

        add     BX, 2

        cmp     CX, 50
        ja      .Boat


        ; Мачта
        mov     AL, 17
       ; mov     DI, 320 * 10 + 159
        mov     DI, DX
        sub     DI, 320 * 119 + 61

.Machta:
        push    DI
        mov     CX, 3
        rep     stosb
        pop     DI

        add     DI, 320

        cmp     DI, 320 * 130
        jb      .Machta


        ; Начало флага на мачте
        mov     AL, 40

        mov     CX, 25
       ; mov     DI, 320 * 10 + 162
        mov     DI, DX
        sub     DI, 320 * 119 + 58

.FlagUp:
        push    DI
        dec     CX
        push    CX
        rep     stosb
        pop     CX
        pop     DI

        add     DI, 320

        cmp     DI, 320 * 18
        jb      .FlagUp

.FlagDown:
        push    DI
        inc     CX
        push    CX
        rep     stosb
        pop     CX
        pop     DI

        add     DI, 320

        cmp     DI, 320 * 26
        jb      .FlagDown


        ; Парус
        mov     AL, 43
        mov     CX, 1
       ; mov     DI, 320 * 30 + 159
        mov     DI, DX
        sub     DI, 320 * 89 + 61

.ParusUp:
        push    DI
        add     CX, 2
        push    CX
        rep     stosb
        pop     CX
        pop     DI

        add     DI, 320

        push    DI
        push    CX
        rep     stosb
        pop     CX
        pop     DI

        add     DI, 320
        sub     DI, 1

        cmp     DI, 320 * 125
        jb      .ParusUp

        ; Пристань
        mov     Al, 19
        mov     DI, 320 * 129 + 280

Pristan:
        mov     CX, 40
        rep     stosb

        add     DI, 280

        cmp     DI, 320 * 160
        jb      Pristan

InputSymbol:
        mov     AH, 08h
        int     21h

        cmp     DX, 320 * 129 + 120
        je      RightSh

        cmp     AL, '0'
        je      Finish

LeftSh:
        cmp     AL, '1'
        jne     Resume
        sub     DX, 2
        jmp     StartDraw

Resume:
        cmp     DX, 320 * 129 + 280
        je      InputSymbol

RightSh:
        cmp     AL, '2'
        jne     InputSymbol
        add     DX, 2
        jmp     StartDraw

Finish:
        ret

bOldMode        db      ?
bOldPage        db      ?