diff --git a/src/toolsrc/codegen.c b/src/toolsrc/codegen.c
index 46ccba5..ca60229 100755
--- a/src/toolsrc/codegen.c
+++ b/src/toolsrc/codegen.c
@@ -544,6 +544,8 @@ void emit_const(int cval)
         printf("\t%s\t$00\t\t\t; ZERO\n", DB);
     else if (cval > 0 && cval < 256)
         printf("\t%s\t$2A,$%02X\t\t\t; CB\t%d\n", DB, cval, cval);
+    else if ((cval&0xFF00) >= 0xFF00)
+        printf("\t%s\t$80,$%02X\t\t\t; CFFB\t%d\n", DB, cval&0xFF, cval&0xFF);
     else
         printf("\t%s\t$2C,$%02X,$%02X\t\t; CW\t%d\n", DB, cval&0xFF,(cval>>8)&0xFF, cval);
 }
diff --git a/src/vmsrc/plvm01.s b/src/vmsrc/plvm01.s
index 787c59c..1da77d1 100644
--- a/src/vmsrc/plvm01.s
+++ b/src/vmsrc/plvm01.s
@@ -118,6 +118,7 @@ OPTBL   !WORD   ZERO,ADD,SUB,MUL,DIV,MOD,INCR,DECR      ; 00 02 04 06 08 0A 0C 0
     !WORD   BRNCH,IBRNCH,CALL,ICAL,ENTER,LEAVE,RET,NEXTOP   ; 50 52 54 56 58 5A 5C 5E
     !WORD   LB,LW,LLB,LLW,LAB,LAW,DLB,DLW           ; 60 62 64 66 68 6A 6C 6E
     !WORD   SB,SW,SLB,SLW,SAB,SAW,DAB,DAW           ; 70 72 74 76 78 7A 7C 7E
+    !WORD   CFFB                                    ; 80 82 84 86 88 8A 8C 8E
 ;*
 ;* DIV TOS-1 BY TOS
 ;*
@@ -399,12 +400,14 @@ ZERO    DEX
     STA ESTKL,X
     STA ESTKH,X
     JMP NEXTOP
-CB  DEX
+CFFB    LDA #$FF
+    !BYTE $2C	; BIT $00A9 - effectively skips LDA #$00, no harm in reading this address
+CB  LDA #$00
+    DEX
+    STA ESTKH,X
     +INC_IP
     LDA (IP),Y
     STA ESTKL,X
-    LDA #$00
-    STA ESTKH,X
     JMP NEXTOP
 ;*
 ;* LOAD ADDRESS & LOAD CONSTANT WORD (SAME THING, WITH OR WITHOUT FIXUP)
diff --git a/src/vmsrc/plvm02.s b/src/vmsrc/plvm02.s
index 7aeb36a..eab214e 100755
--- a/src/vmsrc/plvm02.s
+++ b/src/vmsrc/plvm02.s
@@ -176,6 +176,7 @@ OPTBL	!WORD	ZERO,ADD,SUB,MUL,DIV,MOD,INCR,DECR		; 00 02 04 06 08 0A 0C 0E
 	!WORD	BRNCH,IBRNCH,CALL,ICAL,ENTER,LEAVE,RET,NEXTOP	; 50 52 54 56 58 5A 5C 5E
 	!WORD	LB,LW,LLB,LLW,LAB,LAW,DLB,DLW			; 60 62 64 66 68 6A 6C 6E
 	!WORD	SB,SW,SLB,SLW,SAB,SAW,DAB,DAW			; 70 72 74 76 78 7A 7C 7E
+	!WORD	CFFB                         			; 80 82 84 86 88 8A 8C 8E
 ;*
 ;* ENTER INTO BYTECODE INTERPRETER
 ;*
@@ -731,12 +732,14 @@ ZERO	DEX
 	STA	ESTKL,X
 	STA	ESTKH,X
 	JMP	NEXTOP
-CB	DEX
+CFFB	LDA	#$FF
+    !BYTE $2C	; BIT $00A9 - effectively skips LDA #$00, no harm in reading this address
+CB	LDA	#$00
+	DEX
+	STA	ESTKH,X
 	+INC_IP
 	LDA	(IP),Y
 	STA	ESTKL,X
-	LDA	#$00
-	STA	ESTKH,X
 	JMP	NEXTOP
 ;*
 ;* LOAD ADDRESS & LOAD CONSTANT WORD (SAME THING, WITH OR WITHOUT FIXUP)
diff --git a/src/vmsrc/plvm03.s b/src/vmsrc/plvm03.s
index 4d8f59a..6af00b4 100644
--- a/src/vmsrc/plvm03.s
+++ b/src/vmsrc/plvm03.s
@@ -223,6 +223,7 @@ OPTBL   !WORD   ZERO,ADD,SUB,MUL,DIV,MOD,INCR,DECR              ; 00 02 04 06 08
         !WORD   BRNCH,IBRNCH,CALL,ICAL,ENTER,LEAVE,RET,NEXTOP   ; 50 52 54 56 58 5A 5C 5E
         !WORD   LB,LW,LLB,LLW,LAB,LAW,DLB,DLW                   ; 60 62 64 66 68 6A 6C 6E
         !WORD   SB,SW,SLB,SLW,SAB,SAW,DAB,DAW                   ; 70 72 74 76 78 7A 7C 7E
+        !WORD   CFFB                                            ; 80 82 84 86 88 8A 8C 8E
 ;*
 ;* MUL TOS-1 BY TOS
 ;*
@@ -507,12 +508,14 @@ ZERO    DEX
         STA     ESTKL,X
         STA     ESTKH,X
         JMP     NEXTOP
-CB      DEX
+CFFB    LDA     #$FF
+        !BYTE   $2C             ; BIT $00A9 - effectively skips LDA #$00, no harm in reading this address
+CB      LDA     #$00
+        DEX
+        STA     ESTKH,X
         +INC_IP
         LDA     (IP),Y
         STA     ESTKL,X
-        LDA     #$00
-        STA     ESTKH,X
         JMP     NEXTOP
 ;*
 ;* LOAD ADDRESS & LOAD CONSTANT WORD (SAME THING, WITH OR WITHOUT FIXUP)