1. A method for encoding a series of binary input data bits x into an M=10 run-length limited (2,10) code having a rate R=5/4, to produce a series of code symbols y, the method comprising the steps of: receiving at a seven-state encoder an input data bit set x.sub.0 -x.sub.4 to be encoded into the M=10 run-length limited (2,10) code; and generating in said encoder a code symbol set y.sub.0 -y.sub.3 based on said input data bit set x.sub.0 -x.sub.4 according to the following table: TBL ______________________________________ INPUT OUTPUT NEXT STATE ______________________________________ State 0 0 0000 1 1 0000 2 2 0000 3 3 0000 4 4 0000 5 5 0001 0 6 0002 0 7 0003 0 8 0004 0 9 0005 0 10 0006 0 11 0007 0 12 0008 0 13 0009 0 14 0010 0 15 0020 0 16 0030 0 17 0040 0 18 0050 0 19 0060 0 20 0070 0 21 0080 0 22 0090 0 23 0010 1 24 0020 1 25 0030 1 26 0040 1 27 0050 1 28 0060 1 29 0070 1 30 0080 1 31 0090 1 State 1 0 0100 1 1 0200 1 2 0300 1 3 0400 1 4 0500 1 5 0600 1 6 0700 1 7 0100 2 8 0200 2 9 0300 2 10 0400 2 11 0500 2 12 0600 2 13 0700 2 14 0100 3 15 0200 3 16 0300 3 17 0400 3 18 0500 3 19 0600 3 20 0700 3 21 0100 4 22 0200 4 23 0300 4 24 0400 4 25 0500 4 26 0600 4 27 0700 4 28 0100 5 29 0200 5 30 0300 5 31 0400 5 State 2 0 0000 1 1 0000 6 2 0000 3 3 0000 4 4 0000 5 5 0001 0 6 0002 0 7 0003 0 8 0004 0 9 0005 0 10 0006 0 11 0007 0 12 0008 0 13 0009 0 14 0010 0 15 0020 0 16 0030 0 17 0040 0 18 0050 0 19 0060 0 20 0070 0 21 0080 0 22 0090 0 23 0010 1 24 0020 1 25 0030 1 26 0040 1 27 0050 1 28 0060 1 29 0070 1 30 0080 1 31 0090 1 State 3 0 1001 0 1 1002 0 2 1003 0 3 1004 0 4 1005 0 5 1006 0 6 1007 0 7 1008 0 8 1009 0 9 2001 0 10 2002 0 11 2003 0 12 2004 0 13 2005 0 14 2006 0 15 2007 0 16 2008 0 17 2009 0 18 3001 0 19 3002 0 20 3003 0 21 3004 0 22 3005 0 23 3006 0 24 3007 0 25 3008 0 26 3009 0 27 4001 0 28 4002 0 29 4003 0 30 4004 0 31 4005 0 State 4 0 4006 0 1 4007 0 2 4008 0 3 4009 0 4 5001 0 5 5002 0 6 5003 0 7 5004 0 8 5005 0 9 5006 0 10 5007 0 11 5008 0 12 5009 0 13 6001 0 14 6002 0 15 6003 0 16 6004 0 17 6005 0 18 6006 0 19 6007 0 20 6008 0 21 6009 0 22 7001 0 23 7002 0 24 7003 0 25 7004 0 26 7005 0 27 7006 0 28 7007 0 29 7008 0 30 7009 0 31 8001 0 State 5 0 8002 0 1 8003 0 2 8004 0 3 8005 0 4 8006 0 5 8007 0 6 8008 0 7 8009 0 8 9001 0 9 9002 0 10 9003 0 11 9004 0 12 9005 0 13 9006 0 14 9007 0 15 9008 0 16 9009 0 17 1000 1 18 2000 1 19 3000 1 20 1000 2 21 2000 2 22 3000 2 23 1000 3 24 2000 3 25 3000 3 26 1000 4 27 2000 4 28 3000 4 29 1000 5 30 2000 5 31 3000 5 State 6 0 4000 1 1 5000 1 2 6000 1 3 7000 1 4 8000 1 5 9000 1 6 4000 2 7 5000 2 8 6000 2 9 7000 2 10 8000 2 11 9000 2 12 4000 3 13 5000 3 14 6000 3 15 7000 3 16 8000 3 17 9000 3 18 4000 4 19 5000 4 20 6000 4 21 7000 4 22 8000 4 23 9000 4 24 4000 5 25 5000 5 26 6000 5 27 7000 5 28 8000 5 29 9000 5 30 0800 1 31 0900 1 ______________________________________ wherein said code symbol set y.sub.0 -y.sub.3 is generated based on the input data bit set x.sub.0 -x.sub.4 and the current state of said seven-state encoder when said data bit set x.sub.0 -x.sub.4 is received.