You can test your copy of the distribution diskette, to make sure the copy is accurate, by entering the command CHECK *.* at the DOS prompt. The output should look like this: CRCK ver 4.2B (MS DOS VERSION ) CTL-S pauses, CTL-C aborts --> FILE: READ .ME CRC = 89 EB --> FILE: ESIE .COM CRC = 70 F3 --> FILE: CONFIG .COM CRC = 71 16 --> FILE: MANUAL . CRC = 56 1A --> FILE: TUTOR . CRC = B1 C9 --> FILE: NOVICE . CRC = 63 D7 --> FILE: HISTORY . CRC = DD 31 --> FILE: FINAL .USE CRC = B7 3F --> FILE: ANIMAL . CRC = 6B A8 --> FILE: DOCTOR . CRC = 4C 3E --> FILE: GLASS . CRC = A0 08 --> FILE: ABOARD . CRC = 9B FC --> FILE: ABOARD .DOC CRC = AE 02 --> FILE: GETAWAY . CRC = 7C 82 --> FILE: HEIGHT . CRC = FC C9 --> FILE: HAIR . CRC = 99 4A --> FILE: SUPPORT . CRC = 06 72 --> FILE: CHECK .COM CRC = BD 22 --> FILE: CHECK .TXT CRC = 00 00 ---------------------> SUM OF CRCS = E4 33 DONE Note: the CRC for CHECK.TXT will be incorrect as will be the total, because you cannot write a file's CRC to the file without altering the CRC of the file.