1 assume cs:code
  2
  3 data segment
  4         db 'ACEGIKMOQSUWY13579BD'
  5         db 'BDFHJLNPRTVXZ2468ACE'
  6 data ends
  7
  8 stack segment
  9         dw 8 dup(0)
 10 stack ends
 11
 12 code segment
 13 start:
 14         mov ax,data
 15         mov ds,ax
 16         mov ax,0b800h
 17         mov es,ax
 18         mov ax,stack
 19         mov ss,ax
 20         mov sp,10h
 21
 22         call clear_screen
 23         call greenground
 24         call draw_chrismastree
 25         call over
 26
 27 draw_chrismastree:
 28         mov di,80
 29         mov ah,31
 30         mov al,'*'
 31         call draw
 32         mov cx,7
 33     dxt0:
 34         add di,156
 35         call draw
 36         loop dxt0
 37         mov cx,6
 38     dxt1:
 39         add di,4
 40         call draw
 41         loop dxt1
 42         mov cx,10
 43     dxt2:
 44         add di,156
 45         call draw
 46         loop dxt2
 47         mov cx,10
 48     dxt3:
 49         add di,4
 50         call draw
 51         loop dxt3
 52         mov cx,7
 53     dxt4:
 54         add di,160
 55         call draw
 56         loop dxt4
 57         mov cx,3
 58     dxt5:
 59         add di,4
 60         call draw
 61         loop dxt5
 62         mov cx,7
 63     dxt6:
 64         sub di,160
 65         call draw
 66         loop dxt6
 67         mov cx,10
 68     dxt7:
 69         add di,4
 70         call draw
 71         loop dxt7
 72         mov cx,10
 73     dxt8:
 74         sub di,164
 75         call draw
 76         loop dxt8
 77         mov cx,6
 78     dxt9:
 79         add di,4
 80         call draw
 81         loop dxt9
 82         mov cx,8
 83     dxt10:
 84         sub di,164
 85         call draw
 86         loop dxt10
 87         ret
 88
 89 draw:
 90         add ah,12
 91         mov es:[di],ax
 92         call sleep_1s
 93         ret
 94
 95 greenground:
 96         mov di,0
 97         mov bp,3844
 98         mov cx,25
 99     gg0:
100         push cx
101         mov ah,02h
102         mov si,0
103         mov bx,20
104         mov cx,20
105     gg1:
106         mov al,ds:[si]
107         mov es:[di],ax
108         mov al,ds:[bx]
109         mov es:[bp],ax
110         add di,8
111         add bp,8
112         inc si
113         inc bx
114         loop gg1
115         call sleep_1s
116         sub bp,320
117         pop cx
118         loop gg0
119         ret
120
121 sleep_1s:
122         push cx
123         mov cx,8h
124     sps0:
125         push cx
126         mov cx,0ffffh
127     sps1:
128         loop sps1
129         pop cx
130         loop sps0
131         pop cx
132         ret
133
134 clear_screen:
135         push cx
136         push di
137         mov di,0
138         mov cx,25
139     cses0:
140         push cx
141         mov cx,80
142     cses1:
143         mov word ptr es:[di],0
144         add di,2
145         loop cses1
146         pop cx
147         loop cses0
148         pop di
149         pop cx
150         ret
151
152 over:
153         mov ax,4c00h
154         int 21h
155 code ends
156 end start