-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathdesign_diagram.txt
More file actions
260 lines (231 loc) Β· 16.3 KB
/
Copy pathdesign_diagram.txt
File metadata and controls
260 lines (231 loc) Β· 16.3 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β SNAKE GAME - 8086 ASSEMBLY ARCHITECTURE β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β SYSTEM OVERVIEW β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
βββββββββββββββ
β START β
β (org 100h) β
ββββββββ¬βββββββ
β
βΌ
βββββββββββββββββββββββββββ
β Welcome Screen β
β - Display instructions β
β - Wait for keypress β
ββββββββββββ¬βββββββββββββββ
β
βΌ
βββββββββββββββββββββββββββ
β Initialize Game β
β - Clear screen β
β - Hide cursor β
β - Set snake at (12,40) β
ββββββββββββ¬βββββββββββββββ
β
βΌ
βββββββββββββββββββββββββββ
β MAIN GAME LOOP β
β β
β ββββββββββββββββββββ β
β β Display Score β β
β ββββββββββ¬ββββββββββ β
β βΌ β
β ββββββββββββββββββββ β
β β Draw Food (@) β β
β ββββββββββ¬ββββββββββ β
β βΌ β
β ββββββββββββββββββββ β
β β Draw Snake Head β β
β β (O) β β
β ββββββββββ¬ββββββββββ β
β βΌ β
β ββββββββββββββββββββ β
β β Move Snake β β
β β - Shift array β β
β β - Update head β β
β ββββββββββ¬ββββββββββ β
β βΌ β
β ββββββββββββββββββββ β
β β Check Collision β β
β β with Food β β
β ββββββ¬ββββββββ¬ββββββ β
β β β β
β NO β β YES β
β β βΌ β
β β βββββββββββ β
β β β Grow β β
β β β Score++ β β
β β β NewFood β β
β β ββββββ¬βββββ β
β β β β
β βββββββββ β
β βΌ β
β ββββββββββββββββββββ β
β β Erase Tail β β
β ββββββββββ¬ββββββββββ β
β βΌ β
β ββββββββββββββββββββ β
β β Check Keyboard β β
β β (INT 16h) β β
β ββββββ¬ββββββββ¬ββββββ β
β β β β
β ESCβ βArrow β
β β βΌ β
β β βββββββββββ β
β β βUpdate β β
β β βDirectionβ β
β β ββββββ¬βββββ β
β β β β
β β βΌ β
β β βββββββββββ β
β β β Delay β β
β β β(4 ticks)β β
β β ββββββ¬βββββ β
β β β β
β β ββββββ β
β β βΌ β
β β [LOOP] β
βββββββββͺββββββββββββββββββ
β
βΌ
βββββββββββββββββββ
β EXIT GAME β
β - Show cursor β
β - Return to DOS β
βββββββββββββββββββ
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β MEMORY LAYOUT β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
CODE SEGMENT (CS)
βββββββββββββββββββββββββββββββββββββββ
β 0100h JMP start β βββ
βββββββββββββββββββββββββββββββββββββββ€ β
β DATA SECTION β β
β snake: DW 15 dup(0) [30 bytes] β β
β tail: DW ? [2 bytes] β β
β slen: DW 7 [2 bytes] β β
β cur_dir: DB right [1 byte] β β
β fx, fy: DB 30, 12 [2 bytes] β β
β score: DW 0 [2 bytes] β β
β msg: DB "..." [~100 b] β β
βββββββββββββββββββββββββββββββββββββββ€ β
β CODE SECTION β βββ
β start: ... β
β game_loop: ... β
β move_snake: ... β
β pnum: ... β
βββββββββββββββββββββββββββββββββββββββ
Total: ~600 bytes
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β DATA STRUCTURES β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
SNAKE ARRAY (15 words = 30 bytes)
ββββββββββ¬βββββββββ¬βββββββββ¬ββββββ¬βββββββββ
β [0] β [1] β [2] β ... β [14] β
β HEAD β BODY β BODY β β TAIL β
ββββββββββ΄βββββββββ΄βββββββββ΄ββββββ΄βββββββββ
Each word: [HIGH:Y coord][LOW:X coord]
Example: 0C28h = Row 12, Column 40
DIRECTION CODES (Keyboard Scan Codes)
ββββββββ¬ββββββββ¬ββββββββ
β 48h β UP β β β
β 50h β DOWN β β β
β 4Bh β LEFT β β β
β 4Dh β RIGHT β β β
ββββββββ΄ββββββββ΄ββββββββ
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β BIOS INTERRUPT USAGE β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
INT 10h - VIDEO SERVICES
ββββββββββββββββββββββββββββββββββββββββββββ
β AH=00h Set video mode (80x25 text) β
β AH=02h Set cursor position (DH,DL) β
β AH=05h Select active page β
β AH=09h Write char + attribute β
ββββββββββββββββββββββββββββββββββββββββββββ
INT 16h - KEYBOARD SERVICES
ββββββββββββββββββββββββββββββββββββββββββββ
β AH=00h Read keystroke (blocking) β
β AH=01h Check keystroke (non-blocking) β
ββββββββββββββββββββββββββββββββββββββββββββ
INT 1Ah - TIMER SERVICES
ββββββββββββββββββββββββββββββββββββββββββββ
β AH=00h Read system timer (CX:DX) β
β Used for: delay + randomness β
ββββββββββββββββββββββββββββββββββββββββββββ
INT 21h - DOS SERVICES
ββββββββββββββββββββββββββββββββββββββββββββ
β AH=02h Display character (DL) β
β AH=09h Display string (DS:DX) β
ββββββββββββββββββββββββββββββββββββββββββββ
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β SCREEN LAYOUT (80x25) β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
Row 0: Score:5 β Status line
Row 1: βββββββββββββββββββββββββββββββββββββββ
β β
β @ β Food (red) β
β β
β O*** β Snake β
β β
β β
Row 24: βββββββββββββββββββββββββββββββββββββββ
Legend:
O = Snake head (yellow, 0Eh)
@ = Food (red, 0Ch)
* = Body (not drawn in current version)
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β ALGORITHM FLOW β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
MOVE_SNAKE PROCEDURE
ββββββββββββββββββββββββββββββββββββββ
β 1. Shift array elements β
β FOR i = length-1 DOWN TO 1: β
β snake[i] = snake[i-1] β
β β
β 2. Update head based on direction β
β IF direction = LEFT: β
β X = X - 1 β
β IF direction = RIGHT: β
β X = X + 1 β
β IF direction = UP: β
β Y = Y - 1 β
β IF direction = DOWN: β
β Y = Y + 1 β
β β
β 3. Handle screen wrapping β
β IF X < 0: X = 79 β
β IF X β₯ 80: X = 0 β
β IF Y < 0: Y = 24 β
β IF Y β₯ 25: Y = 0 β
ββββββββββββββββββββββββββββββββββββββ
FOOD COLLISION CHECK
ββββββββββββββββββββββββββββββββββββββ
β IF snake[0].X == food.X AND β
β snake[0].Y == food.Y: β
β score++ β
β length++ β
β Generate new food position β
ββββββββββββββββββββββββββββββββββββββ
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β PERFORMANCE METRICS β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
Game Speed: ~4.5 FPS (222ms per frame)
Timer Resolution: 18.2 Hz (55ms per tick)
Max Snake Length: 15 segments
Memory Usage: ~600 bytes
CPU Usage: <1% (timer-limited, not CPU-limited)
Complexity Analysis:
ββββββββββββββββββββββββ¬ββββββββββββ¬βββββββββββββββ
β Operation β Complexityβ Per Frame β
ββββββββββββββββββββββββΌββββββββββββΌβββββββββββββββ€
β Snake Movement β O(n) β ~100 ΞΌs β
β Food Collision β O(1) β ~10 ΞΌs β
β Display Update β O(n) β ~6 ms β
β Keyboard Poll β O(1) β ~50 ΞΌs β
ββββββββββββββββββββββββ΄ββββββββββββ΄βββββββββββββββ
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β END OF DIAGRAM β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ