################### # BACKUP MANUAL # ################### PER BRINCH HANSEN 14 AUGUST 1975 PURPOSE: COPIES THE ENTIRE DISK TO OR FROM MAGNETIC TAPE. A DISK BACKUP IS STORED AS A SINGLE FILE ON TAPE TERMINATED BY AN END_OF_FILE MARK. THE TAPE MUST BE MOUNTED AND POSITIONED CORRECTLY BEFORE CALLING THE BACKUP PROGRAM. CALL: BACKUP(HOW: OPERATION) USING OPERATION = (READ, WRITE, CHECK) READ COMMAND: DISPLAYS THE MESSAGE PUSH RETURN TO OVERWRITE DISK ON THE CONSOLE. WHEN THE OPERATOR PUSHES THE RETURN KEY ON THE CONSOLE, THE ENTIRE DISK IS OVERWRITTEN WITH PAGES READ FROM A SINGLE TAPE FILE. THE INITIAL PAUSE ENABLES THE OPERATOR TO CALL THE BACKUP PROGRAM STORED ON ONE DISK PACK AND THEN MOUNT ANOTHER DISK PACK BEFORE OVERWRITING IT. WRITE COMMAND: COPIES THE ENTIRE DISK TO TAPE AS A SINGLE FILE. CHECK COMMAND: READS THE ENTIRE DISK AND A SINGLE TAPE FILE AND COMPARES THEM, PAGE BY PAGE, TO DETERMINE, WHETHER THEY ARE IDENTICAL. THIS COMMAND CAN BE USED TO VERIFY THE READABILITY OF A DISK BACKUP AFTER IT HAS BEEN WRITTEN. ERROR MESSAGES: FILE LENGTH INCORRECT THE DISK AND THE TAPE FILE DO NOT CONTAIN THE SAME NUMBER OF PAGES. CHECK ERROR THE DISK AND THE TAPE FILE ARE NOT IDENTICAL.