This chapter covers the use of printers, magnetic tape drives, ^[1] and the UNIX equivalent to batch processing. At first glance, these topics may appear unrelated. What they have in common, however, is that each is an example of multitasking, the ability to perform two or more tasks simultaneously. OpenVMS users perform most multitasking activities through the use of queues and device allocation. One OpenVMS user queues a job to a printer and performs some other interactive task without having to wait until the job is finished printing. Another OpenVMS user reserves a magnetic tape drive for later use while performing an interactive task. A third OpenVMS user submits a CPU-intensive task to a batch queue and, while that is processing, edits a file.

This chapter discusses the extent to which UNIX accommodates multitasking features similar to those implemented in OpenVMS and then goes on to describe features of multitasking unique to UNIX. In UNIX, the printing of files (see Section 7.1) corresponds to OpenVMS: Both systems queue files and typically print them in the order received. The availability of printers to handle UNIX print requests is, of course, site-dependent. Section 7.1 also shows you how to determine the printers available on a UNIX system and how you can use them.

Section 7.2 describes the commands available for reading and writing magnetic tapes. As with printers, the availability of magnetic tape drives and their characteristics are site-dependent. This section...