User's Manual

XEROX LASER PRINTING SYSTEMS TAPE FORMATS MANUAL 12-1
12. 12IBM OS Writer tape
organization
At IBM OS and OS/VS installations, jobs are categorized by class for
the purpose of scheduling job execution by priority and required
computer resources. Similarly, the job's output may also be assigned
to a certain class, which causes the OS or OS/VS system to buffer
the output data to a relatively high-speed device. This buffering
causes the output reports of one or more jobs to be collected under
a single class identifier. The operator then starts up a special job,
which transfers the output reports to a bulk storage device such as
magnetic tape and/or line printer. The special job, which supervises
the report transfer, is called an OS Writer.
An installation may have one or more writers depending on the
particular site's requirements. Usually, however, there are two
standard writers: the Class A Writer supervises reports destined for
output on a line printer. The Class B Writer supervises reports
destined for output on a card punch. An installation generally assigns
a special class of jobs whose output is to be printed by the Xerox
printing system. An example of report creation under an OS Writer is
explained later in this section.
OS Writer report tape format
An OS Writer report tape is an OS Standard label, single-file tape
consisting of stacked reports. Each report is usually separated from
the preceding report by header banner pages, and is separated from
the succeeding report by optional trailer banner pages.
Banner page format A banner page is distinctively formatted to contain the job name and
MSGCLASS in block letters in the middle of the page. Additionally,
there is a row of asterisks or zeros at the edges of a page on the
fanfold perforations. These perforation lines are often overprinted
several times to provide identification of jobs for the operator who
must burst the fanfold for distribution.
The line printer VFU channel value that causes alignment of the
banner page to the perforation is an installation option, but at most
sites the perforation is assigned to channel 9. The skip to channel 9
command is followed by one or more “space zero lines and print”
commands. It is the skip-to-channel command which enables the
system to determine the location of banner pages, and to separate
stacked reports on the OS Writer report tape.
The trailer banner pages (if any) of one report are generally followed
immediately by the header banner page of the next report, with no
intervening delimiter records, DJDE records, tape marks, or tape
labels.
The JCL used in creating the OS Writer report tape is output by OS
or OS/VS to the MSGCLASS specified on the IBM JOB card.