diff --git a/defines.s b/defines.s
index d4b7f84..1a4544e 100644
--- a/defines.s
+++ b/defines.s
@@ -21,6 +21,25 @@ MICROTAN := 1
 .include "defines_microtan.s"
 .endif
 
+.ifdef CONFIG_2C
+CONFIG_2B := 1
+.endif
+.ifdef CONFIG_2B
+CONFIG_2A := 1
+.endif
+.ifdef CONFIG_2A
+CONFIG_2 := 1
+.endif
+.ifdef CONFIG_2
+CONFIG_11A := 1
+.endif
+.ifdef CONFIG_11A
+CONFIG_11 := 1
+.endif
+.ifdef CONFIG_11
+CONFIG_10A := 1
+.endif
+
 .ifdef CONFIG_SMALL
 BYTES_FP		:= 4
 .else
diff --git a/defines_apple.s b/defines_apple.s
index 2eb5084..d411605 100644
--- a/defines_apple.s
+++ b/defines_apple.s
@@ -1,8 +1,8 @@
 ; http://apple2.org.za/gswv/a2zine/GS.WorldView/Resources/GS.TECH.INFO/AppleSoft/
 
 ; configuration
-CONFIG_10A := 1
 CONFIG_11 := 1
+
 CONFIG_IO_MSB := 1 ; all I/O has bit #7 set
 CONFIG_PRINT_CR := 1 ; print CR when line end reached
 CONFIG_SAFE_NAMENOTFOUND := 1
diff --git a/defines_cbm.s b/defines_cbm.s
index 824bce6..34949db 100644
--- a/defines_cbm.s
+++ b/defines_cbm.s
@@ -14,10 +14,6 @@ CONFIG_DATAFLAG := 1
 CONFIG_PRINTNULLS := 1; whether PRINTNULLS does anything
 CONFIG_SPC_IS_CRSR_RIGHT := 1; always print CRSR RIGHT for SPC() (otherwise only for screen output)
 .else
-CONFIG_10A := 1
-CONFIG_11 := 1
-CONFIG_11A := 1
-CONFIG_2 := 1
 CONFIG_2A := 1
 
 CONFIG_DATAFLAG := 1
diff --git a/defines_kbd.s b/defines_kbd.s
index 7b78ea4..48bb0ab 100644
--- a/defines_kbd.s
+++ b/defines_kbd.s
@@ -1,9 +1,4 @@
 ; configuration
-CONFIG_10A := 1
-CONFIG_11 := 1
-CONFIG_11A := 1
-CONFIG_2 := 1
-CONFIG_2A := 1
 CONFIG_2B := 1
 
 CONFIG_NO_POKE := 1
diff --git a/defines_kim.s b/defines_kim.s
index 7318515..9876c65 100644
--- a/defines_kim.s
+++ b/defines_kim.s
@@ -1,6 +1,4 @@
 ; configuration
-CONFIG_10A := 1
-CONFIG_11 := 1
 CONFIG_11A := 1
 
 CONFIG_MONCOUT_DESTROYS_Y := 1
diff --git a/defines_microtan.s b/defines_microtan.s
index 438ae18..2f04ebc 100644
--- a/defines_microtan.s
+++ b/defines_microtan.s
@@ -1,10 +1,4 @@
 ; configuration
-CONFIG_10A := 1
-CONFIG_11 := 1
-CONFIG_11A := 1
-CONFIG_2 := 1
-CONFIG_2A := 1
-CONFIG_2B := 1
 CONFIG_2C := 1
 
 CONFIG_NULL := 1