of the computer center of the University of Erlangen-Nürnberg.
The computer center is a facility that can be used by all institutions
of all faculties of this university to carry out their research and development work.
In addition, the computer center is responsible for the programming training
of the students and employees of the university.
Here in this model you can see a configuration of the computer center,
which is actually located in a climatized space of about 100 square meters.
The basic equipment of the computer center was provided by the German Research Community.
Every problem to be solved by the computer must be formulated in its exact solution.
This means that every single step must be described in a way that can be processed by the computer.
There must be no unclearities. Everything must be clarified to the last detail.
The computer center is a facility that can be used by all faculties of the University of Erlangen-Nürnberg.
The computer center works in a semi-open operation.
This means that the user formulates his tasks in a programming language himself,
then puts together a task package, we call the package a job,
and passes this job to the computer center for processing.
If this process does not go so smoothly,
if the user has difficulties in problem analysis
or if there are certain fundamental difficulties in the formulation of the solution,
then he can turn to one of our employees who can help him.
In addition, this employee can provide him with certain programs or sub-programs
from the computer center's own program library.
Normally, a user logs his self-formulated programs on log maps.
To do this, the computer center provides him with a number of log machines.
Up to 80 letter numbers and special characters can be entered on each log map.
If a user has put together his job, then he puts the log map package in a box
and pushes it into the computer room via a slide.
There he is taught by the operator that the card deck is inserted into the card reader.
The operator can then insert the card deck into the card reader.
There he is taught by the operator that the card deck is inserted into the card reader.
This card reader carries out two reading operations in a row for each log map
and compares the results with each other to eliminate reading errors.
We see here a time loop recording from the inside of the card reader.
In reality, this card reader reads about 20 log maps per second.
You can imagine that at this speed, the cards can be required to be very accurately logged.
It is therefore not recommended to process the cards with the teeth
as one of our youngest employees does here.
Let's follow what he's doing in the computer room.
This business man at the control desk of the computer is currently informing himself about the logging of the log.
From here he can receive notifications of the computer and if necessary intervene in the operation process.
In addition, he has a large number of control lamps in front of him on his control desk,
which light up in the rhythm of the various computer activities.
All log entries and notifications are protocoled on this strip of paper.
The names of the jobs that await their processing in the machine appear on this screen.
Whenever a new job is read into the card reader,
it is inserted into one of these waiting lines by the operating system of the machine.
If the machine has free capacities, it retrieves the job from the waiting line.
This job is the one that best corresponds to these capacities and guarantees the highest utilization.
This computer system can process up to seven user jobs at the same time.
Since only one central computer unit is available,
only one job can perform arithmetic operations.
But as soon as he wants to input or output data,
these jobs are completely independently taken over by small computers located on the periphery,
and the central unit is free.
It is then available to another job.
Each of the number columns on this screen is assigned a specific job.
It gives information about how much time this job takes in the computer itself and in the periphery.
To the operating tasks of the operator, it is also necessary to place magnetic tapes or magnetic plates.
A stack of magnetic plates consists of ten magnetically coated aluminum plates
that can hold a total of 8.2 million characters.
This corresponds to about twice the content of the large tape.
All jobs that have not yet been started are stored on such magnetic plates,
including the one of our user with the flat nose.
As soon as this job has moved forward enough in the queue and space in the machine has become free,
the execution begins.
With this message on the console protocol, followed by a B in the name of the job,
the machine announces the execution.
While the machine is calculating the job, let's take a look inside the electronics of the computer.
Maybe you remember that when the job was entered,
the information did not come directly from the card reader into the machine,
but was first saved on a magnetic plate.
Of course, the job also has an output, an output on the printer.
And just as little as was previously worked directly, is also worked directly here.
First, the entire output is written on one of the magnetic plates.
The termination of the job is announced by this message on the console protocol.
A plotter, which may seem a bit strange at first glance, is the plotter.
However, it is not only used to issue Christmas columns,
but usually to draw technical curves.
In the meantime, a special routine of the operating system has begun,
which is transferred to the printer on the magnetic plate of the output of our job.
It has a supply of 64 different characters,
can recognize thousands of characters,
and from the 135 character product lines that it can record,
it turns out that it can print 130,000 characters in a minute.
We easily calculate that for our standard example,
the large plotter needs about half an hour.
A writer should have the stamina to write 18 days and nights uninterruptedly,
with 200 strokes per minute, in order to achieve this performance.
When a certain amount of endless paper is collected in the output of the printer,
the printer can print the characters.
When a certain amount of endless paper is collected in the output of the printer,
the operator takes out the lists, separates them from each other,
and gives them to the output from which they can pick up the users.
So far, we have seen how our job was processed together with others,
and how its results were issued in the form of a list of results.
This type of job processing is called stack operation.
Another common type of operation is dialogue operation.
In this type of operation, the stack operation does not include all the completed jobs,
but the user leads a conversation with the computer via a participatory station,
a so-called terminal, which can be a television or something similar,
in a specific synthetic language.
In our case, the connection to the computer is established by means of a telephone connection,
and after a few registration formalities, the dialogue can be recorded,
which is carried out on the side of the computer by a rather complicated program,
in which, of course, every single step is given in principle.
In our example, the participant types the line x equals 2 plus 3 as a task,
and the computer answers with the result 5.000 and so on.
A second task line, i equals 2 plus 3, is answered with the result i equals 5.
Why now this distinction between 5.000 and 5 without dots and commas?
Well, of course, the computer has to be able to process numbers with dots after the comma,
i.e. broken numbers.
However, this costs a considerable effort,
and since it is not always necessary to process such broken numbers,
but in many cases, in many counting operations, etc.,
it is possible to work with whole numbers,
the distinction between broken and whole numbers is made from the outset.
In our case, x represents a broken number, i a whole number.
This intersection of typewriters and televisions, which you have seen,
is called a display and is also used as a participant station.
Still, the computer cannot interpret such a free, verbal formulation of the problem as you see here.
The natural language, which presents us all with such minor difficulties,
represents an insurmountable obstacle for it.
To be continued...