diff --git a/system/system.h65 b/system/system.s65
similarity index 79%
rename from system/system.h65
rename to system/system.s65
index 7a9eaad..2d6f3fd 100644
--- a/system/system.h65
+++ b/system/system.s65
@@ -19,31 +19,38 @@ INCLUDE_SYSTEM = 1
 ; 0403 value offset
 ; 0405-04a0 rh high/low, temp high/low, checksum
 
-; ARGUMENTS
-; a,x,y can also be used 
-ARG0   = $10
-ARG1   = $11
-ARG2   = $12
-ARG3   = $13
-ARG4   = $14
-ARG5   = $15
-ARG6   = $16
-ARG7   = $17
-ARG9   = $19
-ARG10  = $1a
-ARG11  = $1b
-ARG12  = $1c
-ARG13  = $1d
-ARG14  = $1e
-ARG15  = $1f
-
 .include "io_W65C22.h65"
 .include "utility.h65"
 
+; ARGUMENTS
+; a,x,y can also be used 
+.segment "ZEROPAGE"
+ARG0:   .res 1
+ARG1:   .res 1
+ARG2:   .res 1
+ARG3:   .res 1
+ARG4:   .res 1
+ARG5:   .res 1
+ARG6:   .res 1
+ARG7:   .res 1
+ARG9:   .res 1
+ARG10:  .res 1
+ARG11:  .res 1
+ARG12:  .res 1
+ARG13:  .res 1
+ARG14:  .res 1
+ARG15:  .res 1
+
+
 ; RETURN VALUE 
 ; in a
 
+.segment "VIA1"
+; IO1:    .res 16
 IO1     = $6000
+
+.segment "VIA2"
+; IO2:    .res 16
 IO2     = $7000
 
 ; struct method