diff --git a/src/libsrc/conio.pla b/src/libsrc/conio.pla
index 861667a..dc55d61 100644
--- a/src/libsrc/conio.pla
+++ b/src/libsrc/conio.pla
@@ -125,17 +125,15 @@ asm grplot
 	INY
 	LDA	(GRSCRN),Y
 	STA	DSTH
+	LDY	ESTKL+1,X
+	LDA	(DST),Y
+	EOR	GRCLR
+	STA	TMPL
 	LDA	#$FF
 	ADC	#$00
 	EOR	#$0F
-	TAY
-	AND	GRCLR
-	STA	TMPL
-	TYA
-	EOR	#$FF
-	LDY	ESTKL+1,X
-	AND	(DST),Y
-	ORA	TMPL
+	AND	TMPL
+	EOR	GRCLR
 	STA	(DST),Y
 	LDY	IPY
 	INX
diff --git a/src/libsrc/dgr.pla b/src/libsrc/dgr.pla
index f5c87c2..23bfeca 100755
--- a/src/libsrc/dgr.pla
+++ b/src/libsrc/dgr.pla
@@ -446,12 +446,10 @@ asm _dgrTileTile
 	STA	ESTKL+4,X
 	DEC	ESTKL+1,X	; DEC STRLEN
 	BNE	-
-+	INX
-	INX
-	INX
-	INX
-	INX
-	INX
++	TXA
+	CLC
+	ADC     #6
+	TAX
 	RTS
 end
 //
diff --git a/src/libsrc/fiber.pla b/src/libsrc/fiber.pla
index ff57168..02c7bc6 100644
--- a/src/libsrc/fiber.pla
+++ b/src/libsrc/fiber.pla
@@ -66,7 +66,7 @@ asm fbrSwap(saveVM, restoreVM)
     STA ESTK,Y
     DEY
     BPL -
-+   TXA
+    TXA
     TAY
 -   LDA $100,Y
     STA (DST),Y
diff --git a/src/libsrc/tone.pla b/src/libsrc/tone.pla
index ff53c52..e95133f 100644
--- a/src/libsrc/tone.pla
+++ b/src/libsrc/tone.pla
@@ -17,15 +17,14 @@ export asm tone2(pitch1, pitch2, duration)
 	INY
 +	STA	DSTL
 	STY	DSTH
-       	LDA	ESTKL+1,X
-	STA	TMPL
+       	LDY	ESTKL+1,X
+	STY	TMPL
 	LDA	ESTKL+2,X
+        TAX
 	CMP	TMPL
 	BNE	+
-	LDA	#$00
-+	STA	TMPH
-	LDY	TMPL
-	LDX	TMPH
+	LDX	#$00
++	STX	TMPH
 	LDA	#$00
 	PHP
 	SEI