another hello world from Notch, showing colour text

hello2.asm

@@ -0,0 +1,37 @@
+; Notch's second "hello word" program.
+; http://i.imgur.com/XIXc4.jpg
+; Supposed to show formatting.
+:start
+  set i, 0
+  set j, 0
+  set b, 0xf100
+:nextchar
+     set a, (data+i)
+     ife a, 0
+        set PC, end
+     ifg a, 0xff
+        set PC, setcolor
+     bor a, b
+     set (0x8000+j), a
+     add i, 1
+     add j, 1
+     set PC, nextchar
+:setcolor
+     set b, a
+     and b, 0xff
+     shl b, 8
+     ifg a, 0x1ff
+         add b, 0x80 ; Add high bit to each character we color. So the character must be 7-bit ASCII
+     add i, 1
+     set PC, nextchar
+:data
+    dat 0x170, "Hello ", 0x2e1, "world", 0x170, ", how are you?", 0
+    ; Color format:
+    ; After processing:
+    ; 0x170 -> b = 0x7000 -> 0111 0000 0XXX XXXX = white(grey) on black
+    ; 0x2e1 -> b = 0xe180 -> 1110 0001 1XXX XXXX = yellow on blue
+    ; b gets OR'd with each character.
+    ; ANSI says: black is 0, white is 7, yellow is 3, blue is 4
+    ; If black is 0 and grey is 7, it's <FORE> <BACK> <EXTRA BIT> or <FORE> <EXTRA BIT> <BACK>
+:end
+    set PC, start