The
IBM
1800 Data Acquisition and Control System was
developed to meet the needs for real-time data acquisition,
analysis, and control. Real-time applications normally require
continuous on-line communication between the system and
some process or operation occuring outside the computer
system. These real-time applications, with continuous
operation, require little operator intervention once started.
In many installations, however, the real-time control
system does not utilize all the computer time. Through
time-sharing, idle computer time can be used to perform
background jobs such
as
data processing
or
scientific com-
putations.
It
is
in this area
that
the operator exhibits his
abilities.
In most installations,
the
tasks
of
the operator are
divorced from those
of
the programmer, system analyst,
and keypunch operator. In some installations, however,
one individual performs more than one
of
these tasks. The
subjects treated in this manual will help the operator learn
to operate the data processing
input/output
devices and
processor-controller console used in an 1800 system instal-
lation.
In most cases, the operator works directly with the
machine. In data processing applications, he must under
stand that he cannot allow the machine to remain idle.
The operator should not
attempt
to supply data which
should have been provided by the programmer. In such
cases, the operator should terminate the
job
and return it
to the programmer for correction. This action minimizes
or eliminates idle computer time.
The Program and Run Book
The system analyst initiates the first steps in developing a
program.
He
analyzes the information supplied
by
the user,
decides upon the most efficient means
of
instructing the
computer
to
process the information, and divides the
problem into segments. Each
pr~blem
segment
is
then
solved by the programmer, who lists the specific steps
required
to
instruct the
computer
to
solve
that
segment.
The programmer writes the instructions for the computer
in
a special programming language. This list
of
instructions
is
called a program.
The program
is
then punched into
IBM
cards (called a
source program deck) by keypunch operators. The com-
The Role
of
the Operator
puter cannot execute a source program because a source
program
is
in a programming language and
not
in machine
language. The source deck
is
then translated during a com·
puter run by a program called an assembler or a compiler,
which produces an object program in machine language.
For simplicity,
we
will refer
to
the
executable program
as
the
"program."
An executable program may be in cards
as
a program deck, or it may be on a disk.
The programmer also supplies a series
of
instructions and
notes (called a run book), which gives the operator specific
information regarding the particular program. The program
deck and the run
book
are delivered to the operator, who
depends on the run book to tell him what he must know to
proceed with the processing operation. For example, the
programmer includes error messages in his program to
describe errors that would occur because
of
incorrect input
data or an incorrect operational procedure. The operator
refers to the run book to determine what corrective action
to take when an error occurs. The run
book
also tells him
which program deck or disk
to
use, which forms to use
in
the printer, and how to continue with the processing when
departures from conventional procedures are necessary.
To this
extent
the operator works with the programmer.
the
run book, which has been prepared by the programmer
for each specific program,
is
used by the operator
as
one
of
his tools while running the program through the computer.
The operator uses
the
program and the machine to complete
the processing
of
data.
He
does not explore all
of
the factors
that determine the structure
of
the program.
Operator Responsibilities
During
the
processing
of
data, the operator
is
responsible
for
all
on-line and off-line system components. On-line
devices attach to the system and operate according to
instructions in the program. At times it
is
desirable to make
one or more
of
these components temporarily unavailable
to
the system (while preventive maintenance
is
being per-
formed, for example). While the component
is
unavailable
to the system, it
is
considered to be off-line. Equipment
that
is
never attached to a particular computer system
is
also termed off-line. Keypunches, sorters, collators, and
reproducers are typical examples
of
off-line equipment.
The Role
of
the Operator
