�"Source filename",S$
 �"Destination filename",D$
 �pass=0 � 2 � 2:[OPTpass
($ LDA#0:STAoldcol:LDA#1:STAnewcol
2 LDA#0:STAflag
< .colourloop
F LDA#0:STAline
P( LDA#&2D:STAhread+1:LDA#&C7:STAhread
Z( LDA#&30:STAlread+1:LDA#&01:STAlread
d' LDA#&2F:STAread+1:LDA#&F8:STAmread
n .lineloop
x LDA#0:STAsubline
�
 .subloop
� LDA#0:STAaddr
�
 .pixloop
� LDY#8:LDA(mread),Y
� �#&AA:CMPcolours,X
� BNEnextpix
� LDXnewcol
�
 .left
� LDAaddr:BEQright
� LDY#0:LDA(mread),Y
� �#&55:CMP#&55:BNEright
�G LDA(mread),Y:�#&AA:STAtemp:LDAcolours,X:LSR A:�A temp:STA(mread),Y
� .right

 LDAaddr:CMP#&7F:BEQup

 LDY#8:LDA(mread),Y

 �#&55:CMP#&55:BNEup

"G LDA(mread),Y:�#&AA:STAtemp:LDAcolours,X:LSR A:�A temp:STA(mread),Y
�

00000000  0d 00 0a 1a 20 e8 22 53  6f 75 72 63 65 20 66 69  |.... ."Source fi|
00000010  6c 65 6e 61 6d 65 22 2c  53 24 0d 00 14 1f 20 e8  |lename",S$.... .|
00000020  22 44 65 73 74 69 6e 61  74 69 6f 6e 20 66 69 6c  |"Destination fil|
00000030  65 6e 61 6d 65 22 2c 44  24 0d 00 1e 1d 20 e3 70  |ename",D$.... .p|
00000040  61 73 73 3d 30 20 b8 20  32 20 88 20 32 3a 5b 4f  |ass=0 . 2 . 2:[O|
00000050  50 54 70 61 73 73 0d 00  28 24 20 4c 44 41 23 30  |PTpass..($ LDA#0|
00000060  3a 53 54 41 6f 6c 64 63  6f 6c 3a 4c 44 41 23 31  |:STAoldcol:LDA#1|
00000070  3a 53 54 41 6e 65 77 63  6f 6c 0d 00 32 12 20 4c  |:STAnewcol..2. L|
00000080  44 41 23 30 3a 53 54 41  66 6c 61 67 0d 00 3c 10  |DA#0:STAflag..<.|
00000090  20 2e 63 6f 6c 6f 75 72  6c 6f 6f 70 0d 00 46 12  | .colourloop..F.|
000000a0  20 4c 44 41 23 30 3a 53  54 41 6c 69 6e 65 0d 00  | LDA#0:STAline..|
000000b0  50 28 20 4c 44 41 23 26  32 44 3a 53 54 41 68 72  |P( LDA#&2D:STAhr|
000000c0  65 61 64 2b 31 3a 4c 44  41 23 26 43 37 3a 53 54  |ead+1:LDA#&C7:ST|
000000d0  41 68 72 65 61 64 0d 00  5a 28 20 4c 44 41 23 26  |Ahread..Z( LDA#&|
000000e0  33 30 3a 53 54 41 6c 72  65 61 64 2b 31 3a 4c 44  |30:STAlread+1:LD|
000000f0  41 23 26 30 31 3a 53 54  41 6c 72 65 61 64 0d 00  |A#&01:STAlread..|
00000100  64 27 20 4c 44 41 23 26  32 46 3a 53 54 41 72 65  |d' LDA#&2F:STAre|
00000110  61 64 2b 31 3a 4c 44 41  23 26 46 38 3a 53 54 41  |ad+1:LDA#&F8:STA|
00000120  6d 72 65 61 64 0d 00 6e  0e 20 2e 6c 69 6e 65 6c  |mread..n. .linel|
00000130  6f 6f 70 0d 00 78 15 20  4c 44 41 23 30 3a 53 54  |oop..x. LDA#0:ST|
00000140  41 73 75 62 6c 69 6e 65  0d 00 82 0d 20 2e 73 75  |Asubline.... .su|
00000150  62 6c 6f 6f 70 0d 00 8c  12 20 4c 44 41 23 30 3a  |bloop.... LDA#0:|
00000160  53 54 41 61 64 64 72 0d  00 96 0d 20 2e 70 69 78  |STAaddr.... .pix|
00000170  6c 6f 6f 70 0d 00 a0 17  20 4c 44 59 23 38 3a 4c  |loop.... LDY#8:L|
00000180  44 41 28 6d 72 65 61 64  29 2c 59 0d 00 aa 17 20  |DA(mread),Y.... |
00000190  80 23 26 41 41 3a 43 4d  50 63 6f 6c 6f 75 72 73  |.#&AA:CMPcolours|
000001a0  2c 58 0d 00 b4 0f 20 42  4e 45 6e 65 78 74 70 69  |,X.... BNEnextpi|
000001b0  78 0d 00 be 0e 20 4c 44  58 6e 65 77 63 6f 6c 0d  |x.... LDXnewcol.|
000001c0  00 c8 0a 20 2e 6c 65 66  74 0d 00 d2 15 20 4c 44  |... .left.... LD|
000001d0  41 61 64 64 72 3a 42 45  51 72 69 67 68 74 0d 00  |Aaddr:BEQright..|
000001e0  dc 17 20 4c 44 59 23 30  3a 4c 44 41 28 6d 72 65  |.. LDY#0:LDA(mre|
000001f0  61 64 29 2c 59 0d 00 e6  1b 20 80 23 26 35 35 3a  |ad),Y.... .#&55:|
00000200  43 4d 50 23 26 35 35 3a  42 4e 45 72 69 67 68 74  |CMP#&55:BNEright|
00000210  0d 00 f0 47 20 4c 44 41  28 6d 72 65 61 64 29 2c  |...G LDA(mread),|
00000220  59 3a 80 23 26 41 41 3a  53 54 41 74 65 6d 70 3a  |Y:.#&AA:STAtemp:|
00000230  4c 44 41 63 6f 6c 6f 75  72 73 2c 58 3a 4c 53 52  |LDAcolours,X:LSR|
00000240  20 41 3a 84 41 20 74 65  6d 70 3a 53 54 41 28 6d  | A:.A temp:STA(m|
00000250  72 65 61 64 29 2c 59 0d  00 fa 0b 20 2e 72 69 67  |read),Y.... .rig|
00000260  68 74 0d 01 04 1a 20 4c  44 41 61 64 64 72 3a 43  |ht.... LDAaddr:C|
00000270  4d 50 23 26 37 46 3a 42  45 51 75 70 0d 01 0e 17  |MP#&7F:BEQup....|
00000280  20 4c 44 59 23 38 3a 4c  44 41 28 6d 72 65 61 64  | LDY#8:LDA(mread|
00000290  29 2c 59 0d 01 18 18 20  80 23 26 35 35 3a 43 4d  |),Y.... .#&55:CM|
000002a0  50 23 26 35 35 3a 42 4e  45 75 70 0d 01 22 47 20  |P#&55:BNEup.."G |
000002b0  4c 44 41 28 6d 72 65 61  64 29 2c 59 3a 80 23 26  |LDA(mread),Y:.#&|
000002c0  41 41 3a 53 54 41 74 65  6d 70 3a 4c 44 41 63 6f  |AA:STAtemp:LDAco|
000002d0  6c 6f 75 72 73 2c 58 3a  4c 53 52 20 41 3a 84 41  |lours,X:LSR A:.A|
000002e0  20 74 65 6d 70 3a 53 54  41 28 6d 72 65 61 64 29  | temp:STA(mread)|
000002f0  2c 59 0d ff                                       |,Y..|
000002f4