diff --git a/src/libsrc/apple/dgrlib.pla b/src/libsrc/apple/dgrlib.pla
index f502a5b..1937ee7 100755
--- a/src/libsrc/apple/dgrlib.pla
+++ b/src/libsrc/apple/dgrlib.pla
@@ -196,9 +196,8 @@ export asm dgrBLT(x, y, width, height, src)#0
         CLC
         ADC     ESTKL+2,X   ; WIDTH
         STA     SRCL
-        LDA     SRCH
-        ADC     #$00
-        STA     SRCH
+        BCC     +++
+        INC     SRCH
         BNE     +++
 +       AND     #$FE
         TAY
@@ -356,9 +355,8 @@ export asm dgrTile(x, y, src)#0
         LDA     SRCL        ; SKIP TO NEXT ROW
         ADC     #$07        ; CARRY = 1
         STA     SRCL
-        LDA     SRCH
-        ADC     #$00
-        STA     SRCH
+        BCC     +++
+        INC     SRCH
         BNE     +++
 +       AND     #$FE
         TAY
diff --git a/src/libsrc/apple/mouse.pla b/src/libsrc/apple/mouse.pla
index 6d5193d..5472b8d 100644
--- a/src/libsrc/apple/mouse.pla
+++ b/src/libsrc/apple/mouse.pla
@@ -270,7 +270,7 @@ CHKSIG: LDY #$05
     LDA (TMPTR),Y
     CMP #$01
     BNE :+
-    LDY #$0C
+    INY
     TXA         ; LOOK FOR MATCHING ID
     CMP (TMPTR),Y
     BNE :+
@@ -283,7 +283,6 @@ CHKSIG: LDY #$05
     LDA TMPTR+1
     CMP #$C8
     BCC CHKSIG
-    SEC
     RTS
 
 ;*