Fixed dotted_quad().

Omitting the middle digit because it is '0' must only be done if the high digit was omitted too (because it was '0'). If the high digit is '1' or '2' (and therefore not omitted) then the middle digit must never be omitted.

ip65/dottedquad_c.s

@@ -35,7 +35,8 @@ _dotted_quad:
   rts
 
 convert_byte:
-; hex to bcd routine taken from Andrew Jacob's code at http://www.6502.org/source/integers/hex2dec-more.htm
+; hex to bcd routine taken from Andrew Jacob's code at
+; http://www.6502.org/source/integers/hex2dec-more.htm
   sed                           ; switch to decimal mode
   lda #$00                      ; ensure the result is clear
   sta tmp1                      ; BCD low
@@ -53,19 +54,23 @@ convert_byte:
   bne :-
   cld                           ; back to binary
 
+  lda tmp1
+  lsr
+  lsr
+  lsr
+  lsr
+  pha
   lda tmp2
   beq :+
   ora #'0'
-  sta dotted_quad,y             ; write x00 if not 0
+  sta dotted_quad,y             ; write x00
+  pla
   iny
-: lda tmp1
-  lsr
-  lsr
-  lsr
-  lsr
-  beq :+
-  ora #'0'
-  sta dotted_quad,y             ; write 0x0 if not 0
+  bne :++                       ; always
+: pla
+  beq :++
+: ora #'0'
+  sta dotted_quad,y             ; write 0x0
   iny
 : lda tmp1
   and #$0F