address all detected similarities to C64 BASIC ROM.

Makefile

@@ -45,3 +45,4 @@ test:	newkern newbasic
 
 testsimilarity:	newkern newbasic src/similarity
 	src/similarity kernal newrom 
+	src/similarity basic newrom 

c64/kernal/scan_keyboard.s

@@ -284,7 +284,7 @@ next_row:
 	lda #$00
 	sta key_bucky_state
 	lda ScanResult+6
-	eor #$ff
+	eor #%10000000
 	and #%10000000     ;// Left shift
 	rol
 	rol
@@ -294,7 +294,7 @@ next_row:
 
 	;; Right shift
 	lda ScanResult+1
-	eor #$ff
+	eor #$10
 	lsr
 	lsr
 	lsr
@@ -305,7 +305,7 @@ next_row:
 	
 	;; Control
 	lda ScanResult+0
-	eor #$ff
+	eor #$04
 	and #$04
 	ora key_bucky_state
 	sta key_bucky_state

strings/02A9008D

@@ -0,0 +1,4 @@
+Fragment / LDA #$00 / STA $xxxx
+
+Store zero in a memory location somewhere.
+Not copyrightable.

strings/034C08

@@ -0,0 +1,3 @@
+fragment / JMP $xx08
+
+Not even a whole instruction. Not copyrightable.

strings/0DD0034C

@@ -0,0 +1,4 @@
+fragment / BNE <skip following JMP instruction> / JMP somewhere
+
+Conditionally jump somewhere.  Would be a single instruction
+on many architectures.  Not copyrightable.

strings/1001CAC8

@@ -0,0 +1,3 @@
+Conditionally decrement X before incrementing Y 
+
+Simple register manipulation. Not copyrightable.

strings/41534943

@@ -0,0 +1,4 @@
+"ASIC" part of the word BASIC
+
+Part of a word, the name of a common programming language.
+Not copyrightable.

strings/48A00098

@@ -0,0 +1,4 @@
+PHA / LDY #$00 / TYA
+
+Save A on stack, load Y and A both with zero.
+Simple register manipulation. Not copyrightable.

strings/49FF2980

@@ -0,0 +1,3 @@
+EOR #$FF / AND #$80
+
+Single instruction. Not copyrightable.

strings/642663

@@ -0,0 +1,4 @@
+List of ASCII/PETSCII keys corresponding to C64 key combinations
+
+This is a list of facts, so is not copyrightable.
+Also too short to have any specific meaning.

strings/68A8B9

@@ -0,0 +1,4 @@
+Restore Y from stack, load A from memory location offset by Y
+
+The 6502 is register poor, so it is very common to pull a register
+from the stack and then use it in some way. Not copyrightable.

strings/68AAA5

@@ -0,0 +1,5 @@
+PLA / TAX / LDA $nn
+
+Restore X register value, load A from ZP memory location.
+Rather common fiddling of register values.
+Not copyrightable.

strings/8A48A9

@@ -0,0 +1,4 @@
+TXA / PHA / LDA #$xx
+
+Save X on stack, load A register with a value.
+Simple register manipulation. Not copyrightable.

strings/981865

@@ -0,0 +1,5 @@
+TYA / CLC / ADC $nn
+
+Perform addition to contents of Y register.
+Would be a single instruction on many architectures.
+Nothing creative. Not copyrightable.

strings/984820

@@ -0,0 +1,6 @@
+TYA / PHA / JSR $xxxx
+
+Save Y on stack and call a routine.
+This is common when calling routines that might corrupt
+a given register.
+Not creative. Not copyrightable.

strings/9D0002E8

@@ -0,0 +1,3 @@
+STA $0200,X / INX
+
+Loop fragment. Not copyrightable

strings/A002A900

@@ -0,0 +1,4 @@
+LDX #$02 / LDA #$00
+
+Load X and A registers with values.
+Not copyrightable.

strings/A9282CA9

@@ -0,0 +1,43 @@
+LDA #$28 / BIT $nnnn
+
+It is a common convention in 6502 programming to allow easy
+skipping over the next two bytes, to use the BIT instruction
+(opcode $2C) for this. This allows code like:
+
+entry1:
+	LDA #$01
+	.byte $2C
+entry2:
+	LDA #$02
+	.byte $2C
+entry3:
+	LDA #$03
+	...
+	; Do something based on value of A
+
+This works because the BIT $nnnn instruction eats the two bytes
+that follows it as arguments, thus preventing the later LDA #$xx
+instructions from being run.  This typically saves some bytes
+compared to do it any other way.
+
+It is used on all 6502 platforms, for example this discussion
+on the trick for the Atari 2600:
+
+http://atariage.com/forums/topic/100922-two-player-sprites-without-vdel/
+
+It is not copyrightable.
+
+Here is an example as we have used it to save space when determining
+the correct width of a line:
+
+	;;  Get pointers to screen/colour RAM source
+	lda screen_line_link_table+0
+	bmi +
+	lda #40
+	.byte $2C 		; BIT $nnnn to skip next instruction
+	*
+	lda #80
+	sta load_or_scroll_temp_pointer+0
+	sta load_save_verify_end_address+0
+
+Only one of the LDA #40 or LDA #80 instructions will be executed.

strings/AA9848

@@ -0,0 +1,5 @@
+TAX / TYA / PHA
+
+Manipulate registers.
+Such transfering values to/from registers and the stack is common
+on 6502. Not copyrightable.

strings/C922D006A5

@@ -0,0 +1,4 @@
+CMP #$22 / BNE <skip a couple instructions> /  LDA $nn
+
+Take a branch based on value of A.  
+Very common. Not copyrightable.

strings/D71860

@@ -0,0 +1,5 @@
+fragment / CLC / RTS
+
+Return from subroutine with C clear.
+C flag is frequently used as a convention for returning success
+of failure from a routine, and thus is encountered quite often.

strings/D71880

@@ -0,0 +1,5 @@
+fragment / CLC / RTS
+
+Clear carry flag before returning from a routine.
+The C flag is often used to indicate success/failure in
+routines. Thus is is not surprising and is not copyrightable.

strings/E90085

@@ -0,0 +1,4 @@
+SBC #$00 / LDA
+
+Perform very small part of an arithmetic calculation.
+Not copyrightable.