diff --git a/03/Makefile b/03/Makefile
index dd06acd..3d71765 100644
--- a/03/Makefile
+++ b/03/Makefile
@@ -1,4 +1,4 @@
-all: out02
+all: out02 out03
 out02: in02 ../02/out01
 	../02/out01
 out03: out02 in03
diff --git a/03/ex03 b/03/ex03
index e586b20..510018e 100644
--- a/03/ex03
+++ b/03/ex03
@@ -39,3 +39,4 @@ div
 call A
 str Here is some text which will be put in the executable!
 ?CaD:label
+
diff --git a/03/in02 b/03/in02
index 11e8cf6..624694e 100644
--- a/03/in02
+++ b/03/in02
@@ -770,6 +770,107 @@ im
 ##38.  ascii '8'
 je
 :-=8   read 8 bytes
+im
+##78.  ascii 'x'
+je
+:-=#
+im
+##64.  ascii 'd'
+je
+:-=#
+im
+##27.  ascii '
+je
+:-=#
+// register transfer. start by writing 48 89
+im
+--tx
+IA
+im
+##2.
+DA
+im
+--wr
+cl
+// get index of first register
+im
+--LI
+BA
+zA
+lb
+BA
+im
+--r#
+cl
+DA
+// get index of first register
+im
+##2.
+BA
+im
+--LI
++B
+BA
+zA
+lb
+BA
+im
+--r#
+cl
+<I
+03  shift left by 3
+BA
+im
+##c0.
+|B    or with 0xc0
+BD
+|B    or with dest
+BA
+im
+--wb   write that byte
+cl
+jm
+:-rl  next line
+::tx
+48
+89
+// get register index of rbx
+::r#
+im
+##41. 'A'
+je
+:-r0
+im
+##42. 'B'
+je
+:-r3
+im
+##43. 'C'
+je
+:-r1
+im
+##44. 'D'
+je
+:-r2
+im
+##49. 'I'
+je
+:-r6
+im
+##4a. 'J'
+je
+:-r7
+im
+##52. 'R'
+je
+:-r5
+im
+##53. 'S'
+je
+:-r4
+jm
+:-!r
+::=#
 // it's a number.
 im
 ##2.
@@ -1105,6 +1206,10 @@ im
 ##53.  'S'
 je
 :-AS
+im
+##30.  '0'
+je
+:-A0
 // it's a number
 im
 ##3.
@@ -1404,6 +1509,10 @@ DA
 im
 ##8. syscall 8 = lseek
 sy
+BA
+im
+##400004.
++B        add address of start of file + 4 bytes to write relative offset
 nA  negate current address
 BR
 +B  get relative address
@@ -2125,6 +2234,36 @@ re
 im
 ##1.
 re
+// return 2
+::r2
+im
+##2.
+re
+// return 3
+::r3
+im
+##3.
+re
+// return 4
+::r4
+im
+##4.
+re
+// return 5
+::r5
+im
+##5.
+re
+// return 6
+::r6
+im
+##6.
+re
+// return 7
+::r7
+im
+##7.
+re
 // exit with code in rax
 ::ex
 JA
@@ -2557,6 +2696,12 @@ DA
 im
 ##8.  lseek
 sy
+// set line number to 0
+im
+--L#
+BA
+zA
+sq
 // now go back to do the second pass
 jm
 :-2p
diff --git a/03/in03 b/03/in03
index dcbf395..ef0640a 100644
--- a/03/in03
+++ b/03/in03
@@ -1,14 +1,35 @@
 ; write to stdout
-J=d1
-I=:hello_world
-D=:hello_world_end
-; calculate length by subtracting end from start
-D-=I
-syscall d1
-J=d42
+B=:hello_world
+call :puts
+J=d0
 syscall x3c
 
 :hello_world
 str Hello, world!
 xa
-:hello_world_end
+x0
+
+; output null-terminated string in rbx
+:puts
+	call :strlen
+	I=D
+	D=A
+	J=d1
+	syscall d1
+	return
+
+; calculate length of string in rbx
+; keeps pointer to start of string in rdx, end of string in rsi
+:strlen
+	; keep pointer to start of string
+	D=B
+	I=B
+	:strlen_loop
+	C=1I
+	?C=0:strlen_loop_end
+	I+=d1
+	!:strlen_loop
+	:strlen_loop_end
+	I-=D
+	A=I	
+	return