MISSILE STRIKE Mark Young of Hull wrote Missile Strike, a simple arcade game for any Spectrum. You must use cursor keys 1 and 2 to move your spaceship and 0 to fire your laser in an attempt to shoot down the missiles threatening the existence of Earth. Lines 1- 9 Read the data for the user-defined graphics. The data is held in line 1040 in binary form, using the BIN command. The information is POKEd into the eight bytes where the layout of the graphics character T is stored. For a full explanation of the process, read chapter 14 of the Spectrum manual. Lines 10- 24 Mainly decorative but also set a few variables to zero for later use. Lines 25- 80 Print instructions for the game if requested. Lines 90- 280 Print the basic screen for the game. Lines 290- 310 Set the initial co-ordinates for your spaceship, which will be represented by the letter D. The co-ordinates are set both for character squares and for the single pixels, so that your laser fire can be drawn at the proper place. Lines 394- 396 Set up the position for the enemy at random. Lines 400- 402 Print your spaceship and get ready to print the laser fire. Lines 405- 425 Adjust the co-ordinates according to which key you press. Lines 439- 445 Variable u holds the length of your laser fire. The other lines draw it depending on the position of your ship. Line 460 If p is less than three you have failed to stop the missile. Line 470 Removes the previously printed missile in preparation to printing it again elsewhere. Line 480 You missed the missile but have another chance to hit it. Line 490 A new missile is required. Line 1040 The DATA statement for the user-defined graphics. Lines 4095-4098 You have destroyed a missile, so the program prints a crude explosion and makes a noise. Lines 5000-5020 Line 5000 makes more noise. Line 5010 and 5015 add to your score and count the number of missiles in w. If you have destroyed 10 missiles you win, otherwise the program returns to 391 for a new missile. Line 5100 Having destroyed 10 missiles you are congratulated and the program plays a tune. Following that, the program will RUN again. Lines 6000-6030 A missile has got through to Earth. Variable v holds the number of failures and if there are more than 10 you lose. Line 6100 You have lost the game and a message is printed. The program will then RUN again.