A file is a set of data combined in an external storage of a computer to solve a certain problem. As it is not worthwhile transporting a single “datum” into the external storage or to read from it, several data are combined to form what Is called a record. This combination takes place on the program level. In addition, on the level of the Job-control cards (see, page 146), it is possible to unite several records to a block. For this purpose, entire data blocks are transported to the external medium (the same method is taken conversely, to read the data). The transformation of records into blocks is automatically made by the operating system. Thus, in the SIMULA program, we have to deal with nothing but records.
Unable to display preview. Download preview PDF.