Author: Fabian Greffrath <fabian+debian@greffrath.com>
Description: Use "P" to pause and resume.

--- invaders-1.0.0.orig/game.c
+++ invaders-1.0.0/game.c
@@ -42,6 +42,21 @@ void changecolors(int c)
         else if (aliencolor<1) aliencolor=15;
 }
 
+void displaypause()
+{
+  uint8 key;
+  bool pressed;
+
+  video_usecolor(6,1);
+  video_putstring(30,10,"    PAUSE    ");
+  video_putstring(30,11,"  PRESS \'P\'  ");
+  video_update();
+  do{
+    key_decode(&key,&pressed);
+    key_polling();
+  } while (!(pressed&&(key=='p')));
+};
+
 void resetgame()
 {
   gameover=false;
@@ -167,6 +182,11 @@ void keywork()
         }
       }
       break;
+    case 'p':
+      if (pressed) {
+        displaypause();
+      }
+      break;
     };
   };
 };
--- invaders-1.0.0.orig/keyboard.c
+++ invaders-1.0.0/keyboard.c
@@ -42,6 +42,7 @@ void key_decode(uint8 *key, bool *presse
     if (c==1) *key='@';
     if (c==0x1c) *key='e';
     if (c==0x39) *key=' ';
+    if (c==0x19) *key='p';
   };
 };