Mainframe Ch 3 & 6

The statement is true because in order for the processor to execute a program instruction, both the instruction itself and the data it references must be present in central storage. This is because the processor needs to access the instruction and the data from memory in order to perform the necessary calculations and operations. Without the instruction and the data in central storage, the processor would not be able to execute the program correctly.

JCL (Job Control Language) is a scripting language used on IBM mainframe operating systems to instruct the system on how to run batch jobs. A few simple kinds of jobs can indeed be defined by JCL that consists solely of a few JOB statements. Therefore, the correct answer is False.

To indicate that a JCL statement is continued on the next line, you should place a comma (,) at the end of the line being continued and start the continuation line with // followed by at least one space. This format is used to ensure that the JCL statement is properly continued and interpreted by the system. The comma (,) at the end of the line indicates that the statement is not complete and needs to be continued, while the // followed by a space at the beginning of the continuation line marks it as a continuation of the previous line.

The correct answer is "SYSTEM DISPLAY and SEARCH FACILITY". SDSF is a mainframe utility program used for displaying and managing the system and job output. It allows users to display and search for specific information within the system. Therefore, "SYSTEM DISPLAY and SEARCH FACILITY" is the most appropriate explanation for the acronym SDSF.

The explanation for the given answer, False, is that mainframe auxiliary storage, also known as secondary storage, is not tightly coupled with the processor itself. Instead, it is located on slower external disk and tape drives. On the other hand, mainframe central storage, also known as primary storage or main memory, is directly connected to the processor and provides faster access to data.

The given statement is false. Auxiliary storage, such as external hard drives or cloud storage, is generally less expensive than central storage, which refers to the main memory or internal storage of a computer system. Auxiliary storage is used for long-term storage of data and is typically cheaper because it offers larger storage capacities at lower costs per unit. Central storage, on the other hand, is faster and more expensive due to its proximity to the processor and its role in actively running programs and storing temporary data.

Mainframe pages are typically 4096 bytes in size. This is a common page size used in mainframe systems. The page size refers to the amount of memory that can be addressed and accessed at one time. A larger page size allows for more efficient memory management and reduces the overhead of managing multiple smaller pages.

To indicate that a JCL statement is continued on the next line, you need to place a comma (,) at the end of the line being continued and start the continuation line with // followed by at least one space. This format allows the JCL interpreter to understand that the statement is being continued and should be treated as a single logical line. The comma (,) indicates that the line is not complete and the // followed by a space indicates the continuation of the statement.

Dynamic address translation (DAT) is the process of translating a virtual address during a storage reference into the corresponding real address. This is typically done by the operating system or hardware to map virtual addresses used by programs into physical addresses in memory. By using DAT, the system can efficiently manage memory and allow multiple programs to share the same physical memory without interfering with each other. This translation is crucial for ensuring that programs can access the correct data in memory and for providing memory protection and security.

The given statement is incorrect. Mainframe auxiliary storage, also known as secondary storage, is located on slower external disk and tape drives, while mainframe central storage, also known as primary storage or main memory, is tightly coupled with the processor and is much faster than auxiliary storage.

The correct answer is //DATAIN DD DISP=OLD,DSN=MY.INPUT1 // DD DISP=OLD,DSN=MY.INPUT2 // DD DISP=SHR,DSN=YOUR.DATA. This JCL sequence correctly illustrates concatenation because it specifies multiple input files using the same DD name (DATAIN) with each file separated by a comma. The DISP parameter is used to specify the disposition of each file, such as whether it is to be opened for reading (DISP=OLD) or shared (DISP=SHR). The DSN parameter is used to specify the dataset name for each input file.

The statement is false because mainframe developers do not need to pay close attention to paging issues while designing and developing a program. Paging is a memory management technique used by the operating system, and it is the responsibility of the operating system to handle paging issues. Mainframe developers focus on writing efficient and optimized code for their programs, but they do not directly deal with the implementation or management of paging.

JCL (Job Control Language) is used for defining and controlling jobs on mainframe computers. A few simple kinds of jobs can indeed be defined by JCL that consists solely of a few JOB statements. Therefore, the statement is true.

The correct answer is "//STEP1 EXEC CCLG". This JCL statement specifies that the procedure named CCLG is being executed in the STEP1 of the job. It is the correct syntax to execute a procedure in JCL. The other options are incorrect because they either use the wrong keyword or syntax to execute a procedure.

This statement is false because in most programming languages, instructions are executed sequentially, meaning that the program does not need to be entirely in central storage before an instruction can execute. Instead, instructions are fetched from memory one at a time and executed immediately. This allows for efficient use of memory as only the necessary instructions and data are loaded into central storage as needed.

The statement is false because JCL (Job Control Language) is a scripting language used for controlling batch processing in mainframe operating systems. It is not responsible for managing file names or their changes. Programs accessing files may need to be modified if the file structure or format changes, but not necessarily if the file name changes. Therefore, the given statement is incorrect.