system,  and  also  for  communicating  with  you,  the operator. While   carrying   out   the   instructions   of   an applications  program  or  a  utility  program,  the  computer is in a program or problem state. While in this state, interrupts   occur   that   return   control   of   the   system resources  to  the  supervisor.  When  this  occurs,  the computer is in the supervisor or control state. When an interrupt occurs, a message to the console operator may be displayed to indicate either a normal or abnormal  condition.  Some  messages  require  a  response on  your  part;  others  do  not.  “File  XXX  now  being loaded,”  or  “PAYROLL1  completed  (EOJ)”  do  not require a response. Other messages, like “Printer Not Ready,” or “No volume label found on pack XXX999,” or  “Insufficient  memory  allocated  for  job  XXX”  do require a response on your part. You may be asking yourself, how do I know what occurred, and how do I respond to a system-generated message? YOU   FOLLOW   PROCEDURES!   Most messages are coded, and you use this code to lookup the meaning  of  the  message  displayed.  These  types  of messages are normally found in the software manuals supplied  by  the  manufacturer.  As  you  become  more experienced,  you  will  quickly  become  familiar  with  the different types of messages and be able to determine the origin  of  the  message  just  by  looking  at  the  identifying codes. Program-Generated  Messages Program-generated  messages  are  those  messages that are displayed by the program as the result of the programmer  wanting  to  inform  you  of  an  available option  or  wanting  you  to  supply  data.  The  program might  display  a  message  such  as  “Enter  expiration date,” or “Option 1 to edit data, Option 2 to update file,” or “Load four-part paper in printer.” Whenever  a  program  message  is  displayed  that requires a response, the run book/sheet along with the documentation   (operator’s   manual,   run   manual) provided by the programmer should explain each and every response or option available and how you are to respond. STARTING  JOBS As an operator, you will be expected to run utility programs and batch jobs. The start up procedures are similar for both; refer to the operator’s manuals and run folders for the specifics for each job you run. The most common application utility programs that you will run will be tape and disk copies, to make backup copies of application  files. While batch jobs are more detailed when it comes to starting them, as long as the run folder is followed there will be no problems. They will have different inputs and outputs required than utility programs. All of the file names and media types will be supplied by the user in the form of an AIS service request. Remember, before starting either an application utility or a batch job, look at and follow the operator’s manual and run folder for the job. DISPLAYING JOB STATUS Using the system console, you can display, by their assigned name, the status of all jobs that are currently being executed. The job status also indicates whether the job is active, stopped, terminated, or canceled but still residing in the CPU; waiting for space in the work area   or   on   disk;   waiting   for   a   printer   or   a communications line; or waiting for you to respond to a message. You can also display the status of the system’s I/O devices to see whether or not they have been varied offline  to  the  system. One of your primary responsibilities is to maintain an   awareness   of   the   jobs   currently   undergoing processing   within   the   system.   Having   the   above information is extremely important to you, as it enables you  to  provide  services  to  the  various  jobs  being processed. The jobs with the highest priorities usually receive immediate attention. Jobs with lower but equal priorities are processed in the order they were entered (loaded) into the system (first-come first-served). Considering these operating constraints, it is easy to understand why the system is in a continuous state of change. Through the use of the display command, you are  able  to  get  an  immediate  picture  of  the  system’s activities. Using  this  information  as  a  frame  of reference, you can determine what actions are necessary to maintain a continuous work flow. RESTARTING A JOB Unfortunately for us, not all jobs processed come to a  normal  end  of  job  (EOJ).  Things  like  program  or machine interrupts, operator errors, bad input data, and incorrect  responses  to  messages  can  cause  a  job  to prematurely or abnormally terminate (ABORT). When this occurs, it is imperative that normal operations be resumed  as  quickly  as  possible.  Error  recovery  must  be 2-5