add more routine descriptions, begin documenting why each is needed

c64/kernal/ffe7.s

@@ -0,0 +1,3 @@
+; $FFE7 - Close all files vector
+; (http://codebase64.org/doku.php?id=base:kernalreference)
+	.word close_all_files

c64/kernal/ffea.s

@@ -0,0 +1,4 @@
+; $FFEA - Update jiffy clock vector
+; (http://codebase64.org/doku.php?id=base:kernalreference)
+
+	.word update_jiffy_clock

c64/kernal/ffed.s

@@ -0,0 +1,4 @@
+; $FFED - Return screen size (X=columns, Y=rows)
+; (http://codebase64.org/doku.php?id=base:kernalreference)
+
+	.word get_screen_size

c64/kernal/fff0.s

@@ -0,0 +1,6 @@
+; $FFF0 - Get/Set cursor location vector
+; (http://codebase64.org/doku.php?id=base:kernalreference)
+; To set: C=0, to get, C=1
+; X=row, Y=column
+
+	.word plot

c64/kernal/fffa.interop

@@ -0,0 +1,2 @@
+# Find a programm that requires working NMIs / RESTORE key use
+

c64/kernal/fffc.interop

@@ -0,0 +1,2 @@
+# No program will work without a working CPU reset vector
+*

c64/kernal/fffe.interop

@@ -0,0 +1,2 @@
+# No program will work without a working CPU IRQ vector
+*