diff --git a/defines_apple.s b/defines_apple.s
index 0e4f668..05d2250 100644
--- a/defines_apple.s
+++ b/defines_apple.s
@@ -10,8 +10,8 @@ CONFIG_SCRTCH_ORDER := 3
 
 ; zero page
 ZP_START0 = $00
-ZP_START = $03
-ZP_HOLE = $3D
+ZP_HOLE1 = $03
+ZP_HOLE2 = $3D
 
 JMPADRS = DSCLEN + 1
 LOWTRX = LOWTR
diff --git a/defines_cbm.s b/defines_cbm.s
index 178daa6..fa11ad0 100644
--- a/defines_cbm.s
+++ b/defines_cbm.s
@@ -30,8 +30,7 @@ CONFIG_PEEK_SAVE_LINNUM := 1
 .ifdef CBM1
 ; zero page
 ZP_START0 = $00
-ZP_START = $57
-ZP_HOLE = $00
+ZP_HOLE1 = $57
 
 CONFIG_NO_EXTRA_GO_PTRS := 1
 
@@ -58,8 +57,7 @@ NULL_MAX		:= $0A
 
 ; zero page
 ZP_START0 = $00
-ZP_START = $00
-ZP_HOLE = $05
+ZP_HOLE2 = $05
 
 CONFIG_NO_EXTRA_GO_PTRS := 1
 
diff --git a/defines_kbd.s b/defines_kbd.s
index 9def941..8b080cb 100644
--- a/defines_kbd.s
+++ b/defines_kbd.s
@@ -13,8 +13,8 @@ CONFIG_SMALL := 1
 ; INPUTBUFFER > $0100
 
 ; zero page
-ZP_START = $06
-ZP_HOLE = $05
+ZP_HOLE1 = $06
+ZP_HOLE2 = $05
 
 JMPADRS         := $0093
 LOWTRX          := $0094                        ; $AB also EXPSGN?
diff --git a/defines_kim.s b/defines_kim.s
index 79f8976..88e479b 100644
--- a/defines_kim.s
+++ b/defines_kim.s
@@ -11,8 +11,7 @@ CONFIG_SCRTCH_ORDER := 2
 
 ; zero page
 ZP_START0 = $00
-ZP_START = $00
-ZP_HOLE = $4E
+ZP_HOLE2 = $4E
 
 JMPADRS = DSCLEN + 1
 LOWTRX = LOWTR
diff --git a/defines_microtan.s b/defines_microtan.s
index edcef16..350a71e 100644
--- a/defines_microtan.s
+++ b/defines_microtan.s
@@ -15,8 +15,8 @@ CONFIG_SCRTCH_ORDER := 1
 
 ; zero page
 ZP_START0 = $17
-ZP_START = $03
-ZP_HOLE = $56
+ZP_HOLE1 = $03
+ZP_HOLE2 = $56
 
 JMPADRS = DSCLEN + 1
 LOWTRX = LOWTR
diff --git a/defines_osi.s b/defines_osi.s
index f294260..6ef36bc 100644
--- a/defines_osi.s
+++ b/defines_osi.s
@@ -7,8 +7,7 @@ CONFIG_SMALL := 1
 
 ; zero page
 ZP_START0 = $00
-ZP_START = $51
-ZP_HOLE = $00
+ZP_HOLE1 = $51
 
 JMPADRS = DSCLEN + 1
 LOWTRX = LOWTR
diff --git a/zeropage.s b/zeropage.s
index da5674a..eb9a914 100644
--- a/zeropage.s
+++ b/zeropage.s
@@ -15,7 +15,9 @@ GOGIVEAYF:
   .endif
 .endif
 
-.res ZP_START
+.ifdef ZP_HOLE1
+.res ZP_HOLE1
+.endif
 
 CHARAC:
 	.res 1
@@ -42,7 +44,9 @@ CPRMASK:
 Z14:
 	.res 1
 
-.res ZP_HOLE
+.ifdef ZP_HOLE2
+.res ZP_HOLE2
+.endif
 
 TEMPPT:
 	.res 1