diff --git a/TODO.txt b/TODO.txt
index c2e8ded..aad9ece 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -9,4 +9,6 @@
 * check for KBD whether it's CONFIG_2 && CONFIG_SMALL (float
   etc.)
 * there must be no platform ifdefs in generic files
-* reconstruct pre-CBM1, i.e. CBM1 without the patches
\ No newline at end of file
+* reconstruct pre-CBM1, i.e. CBM1 without the patches
+* add some comments to every file
+* clean up all CONFIG_*, maybe some should go away
\ No newline at end of file
diff --git a/defines_apple.s b/defines_apple.s
index 23aafc0..9fdced2 100644
--- a/defines_apple.s
+++ b/defines_apple.s
@@ -11,10 +11,10 @@ CONFIG_SCRTCH_ORDER := 3
 BYTES_PER_ELEMENT := 6 ; XXX override
 
 ; zero page
-ZP_START0 = $00
-ZP_START0A = $4F
-ZP_START1 = $0D
-ZP_START2 = $55
+ZP_START1 = $00
+ZP_START2 = $4F
+ZP_START3 = $0D
+ZP_START4 = $55
 
 ;extra ZP variables
 USR				:= $000A
diff --git a/defines_cbm1.s b/defines_cbm1.s
index 9504e01..f8e65eb 100644
--- a/defines_cbm1.s
+++ b/defines_cbm1.s
@@ -39,10 +39,10 @@ CONFIG_PRINTNULLS := 1; whether PRINTNULLS does anything
 CONFIG_SPC_IS_CRSR_RIGHT := 1; always print CRSR RIGHT for SPC() (otherwise only for screen output)
 
 ; zero page
-ZP_START0 = $00
-ZP_START0A = $04
-ZP_START1 = $5A
-ZP_START2 = $65
+ZP_START1 = $00
+ZP_START2 = $04
+ZP_START3 = $5A
+ZP_START4 = $65
 
 ; extra ZP variables
 CURDVC			:= $0003
diff --git a/defines_cbm2.s b/defines_cbm2.s
index 3a2e43f..f91dca9 100644
--- a/defines_cbm2.s
+++ b/defines_cbm2.s
@@ -14,10 +14,10 @@ CONFIG_NO_READ_Y_IS_ZERO_HACK := 1
 CONFIG_PEEK_SAVE_LINNUM := 1
 
 ; zero page
-ZP_START0 = $00
-ZP_START0A = $0D
-ZP_START1 = $03
-ZP_START2 = $13
+ZP_START1 = $00
+ZP_START2 = $0D
+ZP_START3 = $03
+ZP_START4 = $13
 
 ; extra/override ZP variables
 CURDVC			:= $000E
diff --git a/defines_kbd.s b/defines_kbd.s
index 6648f20..583d251 100644
--- a/defines_kbd.s
+++ b/defines_kbd.s
@@ -8,10 +8,10 @@ CONFIG_SCRTCH_ORDER := 3
 CONFIG_SMALL := 1
 
 ; zero page
-ZP_START0 = $00
-ZP_START0A = $0F
-ZP_START1 = $06
-ZP_START2 = $15
+ZP_START1 = $00
+ZP_START2 = $0F
+ZP_START3 = $06
+ZP_START4 = $15
 
 ; extra/override ZP variables
 TXPSV           := $0049
diff --git a/defines_kim.s b/defines_kim.s
index 0230fe3..504d611 100644
--- a/defines_kim.s
+++ b/defines_kim.s
@@ -10,10 +10,10 @@ CONFIG_SAFE_NAMENOTFOUND := 1
 CONFIG_SCRTCH_ORDER := 2
 
 ; zero page
-ZP_START0 = $00
-ZP_START0A = $15
-ZP_START1 = $0A
-ZP_START2 = $63
+ZP_START1 = $00
+ZP_START2 = $15
+ZP_START3 = $0A
+ZP_START4 = $63
 
 ; constants
 STACK_TOP		:= $FC
diff --git a/defines_microtan.s b/defines_microtan.s
index 023218a..094dd94 100644
--- a/defines_microtan.s
+++ b/defines_microtan.s
@@ -10,10 +10,10 @@ CONFIG_SAFE_NAMENOTFOUND := 1
 CONFIG_SCRTCH_ORDER := 1
 
 ; zero page
-ZP_START0 = $17
-ZP_START0A = $2F
-ZP_START1 = $24
-ZP_START2 = $85
+ZP_START1 = $17
+ZP_START2 = $2F
+ZP_START3 = $24
+ZP_START4 = $85
 
 ;extra ZP variables
 USR				:= $0021
diff --git a/defines_osi.s b/defines_osi.s
index fe6861b..c453e2a 100644
--- a/defines_osi.s
+++ b/defines_osi.s
@@ -8,10 +8,10 @@ CONFIG_SCRTCH_ORDER := 3
 CONFIG_SMALL := 1
 
 ; zero page
-ZP_START0 = $00
-ZP_START0A = $0D
-ZP_START1 = $5B
-ZP_START2 = $65
+ZP_START1 = $00
+ZP_START2 = $0D
+ZP_START3 = $5B
+ZP_START4 = $65
 
 ;extra ZP variables
 USR             := $000A
diff --git a/zeropage.s b/zeropage.s
index 1793cc7..cd30c91 100644
--- a/zeropage.s
+++ b/zeropage.s
@@ -2,7 +2,7 @@
 .feature org_per_seg
 .zeropage
 
-.org ZP_START0
+.org ZP_START1
 
 GORESTART:
 	.res 3
@@ -13,7 +13,7 @@ GOAYINT:
 GOGIVEAYF:
 	.res 2
 
-.org ZP_START0A
+.org ZP_START2
 Z15:
 	.res 1
 .ifndef POSX; allow override
@@ -37,9 +37,7 @@ TXPSV:
 INPUTBUFFER:
 .endif
 
-.ifdef ZP_START1
-.org ZP_START1
-.endif
+.org ZP_START3
 
 CHARAC:
 	.res 1
@@ -66,7 +64,7 @@ CPRMASK:
 Z14:
 	.res 1
 
-.org ZP_START2
+.org ZP_START4
 
 TEMPPT:
 	.res 1