diff --git a/src/toolsrc/codegen.c b/src/toolsrc/codegen.c
index 7471bcb..f8dd98a 100755
--- a/src/toolsrc/codegen.c
+++ b/src/toolsrc/codegen.c
@@ -1233,7 +1233,7 @@ int crunch_seq(t_opseq **seq, int pass)
                     if (opnext->code == BINARY_CODE(SHL_TOKEN))
                     {
                         op->code = DUP_CODE;
-                        opnext->code == BINARY_CODE(ADD_TOKEN);
+                        opnext->code = BINARY_CODE(ADD_TOKEN);
                         break;
                     }
                     if (opnext->code == BINARY_CODE(MUL_TOKEN) || opnext->code == BINARY_CODE(DIV_TOKEN))
@@ -1465,7 +1465,10 @@ int crunch_seq(t_opseq **seq, int pass)
                         }
                         else
                         {
-                            for (shiftcnt = 0; shiftcnt < 16; shiftcnt++)
+                            //
+                            // Constants 0, 1 and 2 handled above
+                            //
+                            for (shiftcnt = 2; shiftcnt < 16; shiftcnt++)
                             {
                                 if (op->val == (1 << shiftcnt))
                                 {
@@ -1477,7 +1480,10 @@ int crunch_seq(t_opseq **seq, int pass)
                         }
                         break;
                     case BINARY_CODE(DIV_TOKEN):
-                       for (shiftcnt = 0; shiftcnt < 16; shiftcnt++)
+                        //
+                        // Constant 1 handled above
+                        //
+                        for (shiftcnt = 1; shiftcnt < 16; shiftcnt++)
                         {
                             if (op->val == (1 << shiftcnt))
                             {
diff --git a/src/toolsrc/codeopt.pla b/src/toolsrc/codeopt.pla
index 66e97e4..6e49f7c 100644
--- a/src/toolsrc/codeopt.pla
+++ b/src/toolsrc/codeopt.pla
@@ -288,7 +288,7 @@ def crunch_seq(seq, pass)
                         fin
                         break
                     is DIV_CODE
-                       for shiftcnt = 0 to 15
+                       for shiftcnt = 1 to 15
                             if op=>opval == 1 << shiftcnt
                                 op=>opval      = shiftcnt
                                 nextop->opcode = SHR_CODE
diff --git a/src/vmsrc/apple/plvm01.s b/src/vmsrc/apple/plvm01.s
index 73645fe..de74557 100644
--- a/src/vmsrc/apple/plvm01.s
+++ b/src/vmsrc/apple/plvm01.s
@@ -109,7 +109,7 @@ COMP    LDA     #$FF
 ;* OPCODE TABLE
 ;*
         !ALIGN  255,0
-OPTBL   !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 00 02 04 06 08 0A 0C 0E
+OPTBL   !WORD   ZERO,CN,CN,CN,CN,CN,CN,CN                               ; 00 02 04 06 08 0A 0C 0E
         !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 10 12 14 16 18 1A 1C 1E
         !WORD   MINUS1,BREQ,BRNE,LA,LLA,CB,CW,CS                        ; 20 22 24 26 28 2A 2C 2E
         !WORD   DROP,DROP2,DUP,DIVMOD,ADDI,SUBI,ANDI,ORI                ; 30 32 34 36 38 3A 3C 3E
@@ -388,13 +388,17 @@ LNOT    LDA     ESTKL,X
         STA     ESTKH,X
         JMP     NEXTOP
 ;*
-;* CONSTANT -1, NYBBLE, BYTE, $FF BYTE, WORD (BELOW)
+;* CONSTANT -1, ZERO, NYBBLE, BYTE, $FF BYTE, WORD (BELOW)
 ;*
 MINUS1  DEX
 +       LDA     #$FF
         STA     ESTKL,X
         STA     ESTKH,X
         JMP     NEXTOP
+ZERO    DEX
+        STA     ESTKL,X
+        STA     ESTKH,X
+        JMP     NEXTOP
 CN      DEX
         LSR                     ; A = CONST * 2
         STA     ESTKL,X
diff --git a/src/vmsrc/apple/plvm02.s b/src/vmsrc/apple/plvm02.s
index 9781c0f..3cca995 100755
--- a/src/vmsrc/apple/plvm02.s
+++ b/src/vmsrc/apple/plvm02.s
@@ -132,7 +132,7 @@ VMCORE  =        *
 ;*              *
 ;****************
         !ALIGN  255,0
-OPTBL   !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 00 02 04 06 08 0A 0C 0E
+OPTBL   !WORD   ZERO,CN,CN,CN,CN,CN,CN,CN                               ; 00 02 04 06 08 0A 0C 0E
         !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 10 12 14 16 18 1A 1C 1E
         !WORD   MINUS1,BREQ,BRNE,LA,LLA,CB,CW,CS                        ; 20 22 24 26 28 2A 2C 2E
         !WORD   DROP,DROP2,DUP,DIVMOD,ADDI,SUBI,ANDI,ORI                ; 30 32 34 36 38 3A 3C 3E
@@ -633,13 +633,17 @@ LNOT    LDA     ESTKL,X
         STA     ESTKH,X
         JMP     NEXTOP
 ;*
-;* CONSTANT -1, NYBBLE, BYTE, $FF BYTE, WORD (BELOW)
+;* CONSTANT -1, ZERO, NYBBLE, BYTE, $FF BYTE, WORD (BELOW)
 ;*
 MINUS1  DEX
 +       LDA     #$FF
         STA     ESTKL,X
         STA     ESTKH,X
         JMP     NEXTOP
+ZERO    DEX
+        STA     ESTKL,X
+        STA     ESTKH,X
+        JMP     NEXTOP
 CN      DEX
         LSR                     ; A = CONST * 2
         STA     ESTKL,X
diff --git a/src/vmsrc/apple/plvm03.s b/src/vmsrc/apple/plvm03.s
index d00c54e..db24f80 100755
--- a/src/vmsrc/apple/plvm03.s
+++ b/src/vmsrc/apple/plvm03.s
@@ -143,7 +143,7 @@ JENTRY  !WORD   JITINTRP        ; $A0FA
 ;* OPCODE TABLE
 ;*
         !ALIGN  255,0
-OPTBL   !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 00 02 04 06 08 0A 0C 0E
+OPTBL   !WORD   ZERO,CN,CN,CN,CN,CN,CN,CN                               ; 00 02 04 06 08 0A 0C 0E
         !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 10 12 14 16 18 1A 1C 1E
         !WORD   MINUS1,BREQ,BRNE,LA,LLA,CB,CW,CS                        ; 20 22 24 26 28 2A 2C 2E
         !WORD   DROP,DROP2,DUP,DIVMOD,ADDI,SUBI,ANDI,ORI                ; 30 32 34 36 38 3A 3C 3E
@@ -551,13 +551,17 @@ LNOT    LDA     ESTKL,X
         STA     ESTKH,X
         JMP     NEXTOP
 ;*
-;* CONSTANT -1, NYBBLE, BYTE, $FF BYTE, WORD (BELOW)
+;* CONSTANT -1, ZERO, NYBBLE, BYTE, $FF BYTE, WORD (BELOW)
 ;*
 MINUS1  DEX
 +       LDA     #$FF
         STA     ESTKL,X
         STA     ESTKH,X
         JMP     NEXTOP
+ZERO    DEX
+        STA     ESTKL,X
+        STA     ESTKH,X
+        JMP     NEXTOP
 CN      DEX
         LSR                     ; A = CONST * 2
         STA     ESTKL,X
diff --git a/src/vmsrc/apple/plvm802.s b/src/vmsrc/apple/plvm802.s
index baf41b6..6015ebc 100644
--- a/src/vmsrc/apple/plvm802.s
+++ b/src/vmsrc/apple/plvm802.s
@@ -258,7 +258,7 @@ VMCORE  =        *
 ;*              *
 ;****************
         !ALIGN  255,0
-OPTBL   !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 00 02 04 06 08 0A 0C 0E
+OPTBL   !WORD   ZERO,CN,CN,CN,CN,CN,CN,CN                               ; 00 02 04 06 08 0A 0C 0E
         !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 10 12 14 16 18 1A 1C 1E
         !WORD   MINUS1,BREQ,BRNE,LA,LLA,CB,CW,CS                        ; 20 22 24 26 28 2A 2C 2E
         !WORD   DROP,DROP2,DUP,DIVMOD,ADDI,SUBI,ANDI,ORI                ; 30 32 34 36 38 3A 3C 3E
@@ -491,7 +491,7 @@ LCDEFCMD =      *-28            ; DEFCMD IN LC MEMORY
 ;*               *
 ;*****************
         !ALIGN  255,0
-OPXTBL  !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 00 02 04 06 08 0A 0C 0E
+OPXTBL  !WORD   ZERO,CN,CN,CN,CN,CN,CN,CN                               ; 00 02 04 06 08 0A 0C 0E
         !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 10 12 14 16 18 1A 1C 1E
         !WORD   MINUS1,BREQ,BRNE,LA,LLA,CB,CW,CSX                       ; 20 22 24 26 28 2A 2C 2E
         !WORD   DROP,DROP2,DUP,DIVMOD,ADDI,SUBI,ANDI,ORI                ; 30 32 34 36 38 3A 3C 3E
@@ -849,14 +849,14 @@ ORI     INY                     ;+INC_IP
 ;* LOGICAL NOT
 ;*
 LNOT    PLA
-        BEQ     MINUS1
-        PEA     $0000
-        JMP     NEXTOP
+        BNE     ZERO
 ;*
-;* CONSTANT -1, NYBBLE, BYTE, $FF BYTE, WORD (BELOW)
+;* CONSTANT -1, ZERO, NYBBLE, BYTE, $FF BYTE, WORD (BELOW)
 ;*
 MINUS1  PEA     $FFFF
         JMP     NEXTOP
+ZERO    PEA     $0000
+        JMP     NEXTOP
 CN      TXA
         LSR                     ; A = CONST * 2
         PHA
diff --git a/src/vmsrc/apple/plvmjit02.s b/src/vmsrc/apple/plvmjit02.s
index 54c2820..8dc1396 100755
--- a/src/vmsrc/apple/plvmjit02.s
+++ b/src/vmsrc/apple/plvmjit02.s
@@ -206,7 +206,7 @@ VMCORE  =        *
 ;*              *
 ;****************
         !ALIGN  255,0
-OPTBL   !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 00 02 04 06 08 0A 0C 0E
+OPTBL   !WORD   ZERO,CN,CN,CN,CN,CN,CN,CN                               ; 00 02 04 06 08 0A 0C 0E
         !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 10 12 14 16 18 1A 1C 1E
         !WORD   MINUS1,BREQ,BRNE,LA,LLA,CB,CW,CS                        ; 20 22 24 26 28 2A 2C 2E
         !WORD   DROP,DROP2,DUP,DIVMOD,ADDI,SUBI,ANDI,ORI                ; 30 32 34 36 38 3A 3C 3E
@@ -397,7 +397,7 @@ LCDEFCMD =      *               ;*-28            ; DEFCMD IN LC MEMORY
 ;*               *
 ;*****************
         !ALIGN  255,0
-OPXTBL  !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 00 02 04 06 08 0A 0C 0E
+OPXTBL  !WORD   ZERO,CN,CN,CN,CN,CN,CN,CN                               ; 00 02 04 06 08 0A 0C 0E
         !WORD   CN,CN,CN,CN,CN,CN,CN,CN                                 ; 10 12 14 16 18 1A 1C 1E
         !WORD   MINUS1,BREQ,BRNE,LA,LLA,CB,CW,CSX                       ; 20 22 24 26 28 2A 2C 2E
         !WORD   DROP,DROP2,DUP,DIVMOD,ADDI,SUBI,ANDI,ORI                ; 30 32 34 36 38 3A 3C 3E
@@ -797,13 +797,17 @@ LNOT    LDA     ESTKL,X
         STA     ESTKH,X
         JMP     NEXTOP
 ;*
-;* CONSTANT -1, NYBBLE, BYTE, $FF BYTE, WORD (BELOW)
+;* CONSTANT -1, ZERO, NYBBLE, BYTE, $FF BYTE, WORD (BELOW)
 ;*
 MINUS1  DEX
 +       LDA     #$FF
         STA     ESTKL,X
         STA     ESTKH,X
         JMP     NEXTOP
+ZERO    DEX
+        STA     ESTKL,X
+        STA     ESTKH,X
+        JMP     NEXTOP
 CN      DEX
         LSR                     ; A = CONST * 2
         STA     ESTKL,X