diff -ur orig/code/classes.h p1/code/classes.h
--- orig/code/classes.h	2003-08-18 07:48:23.000000000 -0500
+++ p1/code/classes.h	2005-07-17 22:21:34.000000000 -0500
@@ -91,6 +91,33 @@
 
 	public:
 
+	// Added July 2005 by Jason Bucata (jbucata@tulsaconnect.com)
+	// Needed to avoid type over/underflow in addition.
+	// I'm using references as that's more idiomatic C++
+	// (though I'm avoiding the temptation to try out templates here).
+
+	static void safeAdd(signed char& in, signed char add, int low, int high)
+	{
+		int temp = ((int)in) + ((int)add);
+		if (temp < low)
+			in = low;
+		else if (temp > high)
+			in = high;
+		else
+			in = temp;
+	}
+
+	static void safeAdd(unsigned char& in, unsigned char add, int low, int high)
+	{
+		int temp = ((int)in) + ((int)add);
+		if (temp < low)
+			in = low;
+		else if (temp > high)
+			in = high;
+		else
+			in = temp;
+	}
+
 	static void limitChar(signed char *in, int low, int high)
 	{
 		if (*in < low)
diff -ur orig/code/collectable.cpp p1/code/collectable.cpp
--- orig/code/collectable.cpp	2003-08-18 07:48:23.000000000 -0500
+++ p1/code/collectable.cpp	2005-07-17 22:24:18.000000000 -0500
@@ -345,7 +345,11 @@
 						break;
 
 					case P_PLASMA_AMMO:
-						Math::limitChar(&(player.ammo[0] += collectable->value), 0, currentGame.maxPlasmaAmmo);
+						// Changed July 2005 by Jason Bucata (jbucata@tulsaconnect.com)
+						// Use safeAdd to avoid byte overflow in the add
+						// before it can be corrected by the applied limits.
+						//Math::limitChar(&(player.ammo[0] += collectable->value), 0, currentGame.maxPlasmaAmmo);
+						Math::safeAdd(player.ammo[0], collectable->value, 0, currentGame.maxPlasmaAmmo);
 						if (player.ammo[0] == currentGame.maxPlasmaAmmo)
 							sprintf(temp, "Plasma cells at Maximum");
 						else