Added (72,64) codes to the textual description.

diff --git a/hamming.txt b/hamming.txt
index 8391ba386f33160049cec135b8cafa746e487d38..ba6f5f38a1979aa679ef7ac32e77b488dc01ad93 100644 (file)
--- a/hamming.txt
+++ b/hamming.txt
@@ -59,3 +59,38 @@ p3: 01 c7 8f 0f
 p4: 00 3f 80 ff
 p5: 00 00 7f ff
 p6: 03 b4 e9 96
+
+
+Finally, expansion to truncated (127,120) -> (71,64):
+
+   ab-c---d-------e---------------f-------------------------------g-------  
+p1 - x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x
+p2  -x xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx  xx  xx
+p3    -xxx    xxxx    xxxx    xxxx    xxxx    xxxx    xxxx    xxxx    xxxx
+p4        -xxxxxxx        xxxxxxxx        xxxxxxxx        xxxxxxxx        
+p5                -xxxxxxxxxxxxxxx                xxxxxxxxxxxxxxxx
+p6                                -xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+p7                                                                -xxxxxxx
+
+Reordering:
+   
+   ----------------------------------------------------------------  
+p1 xx xx x x xx x x x x x x xx x x x x x x x x x x x x x x xx x x x
+p2 xxx x xx xxxx xx xx xx xx x xx xx xx xx xx xx xx xx xx xx xx  xx
+p3  xxx   xxxx   xxxx    xxxx   xxxx    xxxx    xxxx    xxxx   xxxx
+p4     xxxxxxx       xxxxxxxx       xxxxxxxx        xxxxxxxx       
+p5            xxxxxxxxxxxxxxx               xxxxxxxxxxxxxxxx
+p6                           xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+p7                                                          xxxxxxx
+
+Bit masks, with extra computed parity bit:
+
+p1: 0xDAB5556AAAAAAAD5
+p2: 0xEB7B6DADB6DB6DB3
+p3: 0x71E3C3C78787878F
+p4: 0x0FE03FC07F807F80
+p5: 0x001FFFC0007FFF80
+p6: 0x0000003FFFFFFF80
+p7: 0x000000000000007F
+p8: 0xB02DC4C0E409C0E9
+