252 lines
9.2 KiB
Plaintext
252 lines
9.2 KiB
Plaintext
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BLITZKRIEG - Docs sheet for the 32k Apple ][
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Programmed by Mark Cross for Programma -- 1980
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Compiled by Paula (I also fixed hex typos in original Programma doc)
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Rev.3/1981
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------------------------------------------------------------------------------
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Cassette loading address from monitor: 200.4000R then 800G to run.
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GAME PLAY
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---------
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Use the paddle or keyboard to aim your anti-aircraft gun and shoot down the
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enemy planes! Bombers and three kinds of fighters fly overhead. If a plane
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flies into another plane's debris, it will explode. Some pilots are inept
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and fly into other planes, causing you to gain points! And the debris from
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that crash could gain you more free points! And so on...
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The game ends when your gun runs out of bullets, or one of the bombers drops
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a bomb close enough to your gun to blow you up.
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------------------------------------------------------------------------------
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MEMORY USAGE
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------------
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$0000-0011 - Temporary storage
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$0800-0B16 - Slightly modified Apple hi-res routines
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$0B19-254F - Main program
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$38D0-3FFF - Shape table
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$4000-5FFF - Hi-Res screen memory
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MODIFICATIONS
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-------------
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The game has several adjustments to customize it to each user. These have been
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pre-set, but can be changed as discussed below. Do this for each change:
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1) - Load the program.
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2) - In Integer Basic (or the monitor), make the changes. The Blitzkrieg
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program occupies the same place in memory as Applesoft programs. It
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is possible to load, modify and run Blitzkrieg only if there is NO
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Applesoft program!
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3) - Optional: Resave the new version of the game:
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To tape from monitor: 200.4000W
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From DOS: BSAVE BLITZKRIEG, A2048, L14336
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Run it with CALL 2048 -or- 800G from the monitor
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SPEED
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-----
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The program asks you whether you want to modify some things before starting.
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This gives you a chance to set the speed. Asking for speed 9 makes the game
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run as fast as possible. It also makes your score higher.
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COLORS
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------
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The background is originally black, and the scene is drawn in white. These
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colors can be reversed when the program gives you a chance to make
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modifications.
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NOISES
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------
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The debris makes sounds as it flies through the air. This sounds like
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cracking, buzzing, or a steady tone depending on the speed of the game.
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The noise can be disabled by POKEing zero into locations 6960 and 6961
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($1B30 and $1B31). Restore the noises with POKE 6960,48 and POKE 6961,192.
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AMMUNITION
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----------
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The starting ammo is set at 100. It can be increased by POKEing a number
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up to 255 ($FF) into location 3148 ($C4C).
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NEAR MISSES
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-----------
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Some anti-aircraft shells have proximity fuses that explode if they get close
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to a plane. The shells in this game have the same ability. If they get close
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to a plane, then the plane will blow up. The closeness required is a number
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in location 4064 ($FE0). This number is originally 5. It can be decreased to
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1 for a hard game, or increased to 8 for an easier game.
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NUMBER OF AIRPLANES
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-------------------
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A new plane is created about once every 32 internal program time units. The
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frequency of new planes can be adjusted by POKEing a number into location
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5419 ($141D). This number is originally 31 ($1F).
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Try changing it to these numbers:
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7 ($07) = Four times the original number of planes
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15 ($0F) = Twice the original number of planes
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31 ($1F) = Original number of planes
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63 ($3F) = Half the original number of planes
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Other numbers will make the planes come in irregularly spaced groups.
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DIRECTION OF FLIGHT
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-------------------
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One-fourth of the planes fly from right to left, permitting collisions. You
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can make all the planes fly from left to right by POKEing the number 224 ($E0)
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into locations 5175 thru 5179 ($1437 thru $143B).
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-= Individual Plane Speeds =-
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Plane Type Location Original Speed
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---------- ---------- ---------------------
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Rightward Bomber 5210 $145A 4
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Rightward Big Fighter 5218 $1462 6
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Rightward Med Fighter 5226 $146A 6
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Rightward Small Fighter 5230 $146E 5
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Leftward Bomber 5293 $14AD -4 (Hex) = 252 Decimal
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Leftward Big Fighter 5301 $14B5 -6 (Hex) = 250 Decimal
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Leftward Med Fighter 5309 $14BD -6 (Hex) = 250 Decimal
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Leftward Small Fighter 5313 $14C1 -5 (Hex) = 253 Decimal
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NUMBER OF BOMBERS
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-----------------
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You can control the types of airplanes using the "M" option when the program
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starts. Bombers are very easy to hit, but too many bombers will make it hard
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to avoid getting bombed.
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NUMBER OF BOMBS DROPPED
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-----------------------
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A bomb is dropped by some bombers every 4 program time units if there is a
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bomber on the screen. This can be changed. POKE a new number into location
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5338 ($14DA). The number is 3 originally. A larger number will get you fewer
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bombs. The number POKEd into this location must be a member of the series
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3, 7, 11, 15, 19, 23, 27, 31,... Example: POKE 5338,255 ($14DA w. $FF) will
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nearly disable the bombers for a young child who can't take the tension in
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the original game.
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DEBRIS
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------
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Sometimes the screen gets too full of debris. The amount of debris per ex-
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plosion is controlled by the number 254 ($FE) stored in location 6174 ($181E).
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Less debris would make a faster game.
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252 ($FC) = No debris at all
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253 ($FD) = 5 dots per explosion
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254 ($FE) = 10 dots per explosion (original game value)
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255 ($FF) = 15 dots per explosion
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0 ($00) = 20 dots per explosion
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1 ($01) = 25 dots per explosion
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2 ($02) = 30 dots per explosion
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HIGH SCORE
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----------
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The previous high score is stored in locations 2901 and 2902 ($B55 and $B56)
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inside the program code. It is automatically saved along with the program. If
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this number ever gets impossibly high, you can reset it. The simplest reset is
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to POKE a 0 into both locations 2901 and 2902.
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SHAPE TABLE
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-----------
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An Apple format shape table of 136 shapes is stored in locations 14544 ($38D0)
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through 16383 ($3FFF). The shapes are listed below. All of the printing
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characters (1-8, 21, 32-127) are in a 5x7 matrix with the shape starting at
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the upper left corner of the drawing. The other shapes start drawing in their
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center.
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Shapes
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------
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1 - Box - 5 wide x 7 high
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2 - Solid 5x7 rectangle - draws black to erase something.
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3 - Arrow - Upper right
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4 - Arrow - Straight up
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5 - Arrow - Lower left
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6 - Arrow - Upper left
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7 - Alpha
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8 - Arrow - Straight left
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9 - Rightward bomber
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10 - Rightward big fighter
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11 - Rightward medium fighter
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12 - Rightward small fighter
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13 - Leftward bomber
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14 - Leftward big fighter
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15 - Leftward medium fighter
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16 - Leftward small fighter
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17 - Airplane seen from above #1
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18 - Airplane seen from above #2
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19 - Airplane seen from above #3
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20 - Very small tank (can be magnified and rotated)
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21 - Rightward arrow
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22 - Slightly larger gun
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23 - 2x2 square
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24 - Plus
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25 - 6x6 diamond - solid
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26 - 7x7 ball
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27 - Tie Fighter
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28 - X-wing fighter
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29 - 5 unit horizontal line
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30 - 5 unit vertical line
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31 - 6 pointed star (explosion)
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32 - Blank space
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- ASCII Characters -
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33 - ! 69 - E 105 - i
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34 - " 70 - F 106 - j
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35 - # 71 - G 107 - k
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36 - $ 72 - H 108 - l
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37 - % 73 - I 109 - m
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38 - & 74 - J 110 - n
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39 - ' 75 - K 111 - o
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40 - ( 76 - L 112 - p
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41 - ) 77 - M 113 - q
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42 - * 78 - N 114 - r
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43 - + 79 - O 115 - s
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44 - , 80 - P 116 - t
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45 - - 81 - Q 117 - u
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46 - . 82 - R 118 - v
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47 - / 83 - S 119 - w
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48 - 0 84 - T 120 - x
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49 - 1 85 - U 121 - y
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50 - 2 86 - V 122 - z
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51 - 3 87 - W 123 - {
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52 - 4 88 - X 124 - Vertical line
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53 - 5 89 - Y 125 - }
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54 - 6 90 - Z 126 - ~
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55 - 7 91 - [ 127 - Left arrow
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56 - 8 92 - \ 128 - Small 4x4 ball
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57 - 9 93 - ] 129 - 7x7 open circle
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58 - : 94 - ^ 130 - 11x12 open circle (tree-top)
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59 - ; 95 - Underline 131 - Gun in airplanes game
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60 - < 96 - Single quote 132 - Race car #1
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61 - = 97 - a 133 - Race car #2
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62 - > 98 - b 134 - Bomb with partial tail fin
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63 - ? 99 - c 135 - Rocket
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64 - @ 100 - d 136 - Falling bomb
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65 - A 101 - e
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66 - B 102 - f
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67 - C 103 - g
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68 - D 104 - h
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