OPREMA THE ZEISS COMPUTING MACHINE

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00810A006700700004-0
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 4
• Document Creation Date: December 21, 2016
• Document Release Date: September 26, 2008
• Sequence Number: 4
• Publication Date: May 16, 1955
• Content Type: REPORT

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C r^EN TRAL IN TELLI0- Ni CE .&G&WCY
INFORMATION REPORT
East Germany
OPREMA, this Zeiss Computing Machine
DATE OF INFO.
PLACE ACQUIRED
DATE ACQUIRED
This material contains information affecting the
National Defense of the United States within the
meaning of the Espionage Laws, Title 18, U.S.C.
Secs. 793 and 794, the transmission or revel-
ation of which in any manner to an unauthorized
person is prohibited by law.
REPORT
REQUIREMEN
REFERENCES
DATE DISTR.
NO. OF PAGES L
16 May 1955
THE SOURCE EVALUATIONS IN THIS REPORT ARE DEFINITIVE.
THE APPRAISAL OF CONTENT IS TENTATIVE.
(FOR KEY SEE REVERSE)
1. In early 1955, development of a relay-operated computer for optioa125X1
calculations was completed at VEB Carl Zeiss, Je~10A . The name of the
computer is O.PREMA (Optische Rechenmasohine). The development was o
carried out under the oupervision of Dr. l?. Kaemmerer of the Zeiss firm.
iia many as 200 technicians worked on the development at one time or
another. Prof. N. Joachim Lehmann of the Institute for Bpplied Math-
ematics at Dresden Technical University repeatedly provided scientific
advice to the Zeiss team engaged in the development of the computer.
The OiREMA computer was comploted in two models which are
as well able to control each other as to carry out calculations inde-
pendently from each other.
2. The general principles upon which the Zeiss machine was built and
specific technical details on the machine are contained in a secret
report which Dr. W. Kaemmerer orwarded to the East German 4,cade of
Sciences in early March 1955.
The program-controlled computing machine of VEB Carl Zeiss-Jena
a. In May 1954 VEB Carl Zeiss, Jena, was ordered to develop a program-
controlled computing installation mainly for the purpose of
carrying out calculations of the enterprise. Deirelopme*#-and con-
struction of the machine were taken up immediately and at the
same time. after seven and a half months, the machine was completed.
Operation of several large construction components was already
started during the period of development.
b. The computer, consisting of two twin machines, occupies an area of
55 square meters in a large room which has a floor surface of 740
square meters. The following tequiremaats were to be met:
STATE 1_
ARMY Ll_
NAVY tl X AIR ,X FBI AEC
25X1
25X1
INnto Washington .1 1rih ,ti- indicated by 'Y rioli r1 trjhutinn h"" "I"
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U.perctin,; safety, calculating safety, highest possible calculation speed
and longest, possible life of the machine. These demands were to be
reasonably weighed against various possibilities of computer construc-
tion available at the present level of technology. Machines using
electron tubes presorL:t_ adyantagQ$f ..calculating speed, Operating
safety, however, is greater with relay-operated machines. The idea of
using transistors had to be discarded because their mass production is
not yet possible.
c. Since in general the number of necessary digits amounts to about 4:0 dual
digits, one can shorten the calculating time by the factor 40 if one sets
out to construct the machine as a "parallelim&ohine", i.e. all digits
of a figure will be processed at the same time. However, since the
width is thus increased forty times, the number of relays will be
correspondingly higher. This is no drawback because the relays will
not suffer from weal It if the machine is built expertly and they
thus represent a one-time expenditure only (contrary to tubes). More-
over, construction of the control inetallalion is less complicated in a
parallel system than in a serial system. t is understood that a tube-
operated serial machine works about 25 times faster than a parallel
machine; however, this factor can be reluced to about 8 through special
construction of the parallel machine* ube-operated machines are fre-
quently constructed as mono-address machines in order to reduce the
number of construction elements subjected to wears' '. Ray-operated
machines, however, can use the three-address system without disadvantages
d. There is only one method of giving . . figures to the machine, namely by
indicating to the machine the number of that memory (Speioherregister)
where these figures are stored. In a three-address machine, addition
is a basic operations two figures are given.,: to the machine by means
of two addresses and the operation results in a third figure, their
sum, which by means of a third address is stored or "written" in a certain
place. The mono-address machine, however, splits the addition into
three individual operations. The first operation command with the aid
of the address attached to it fetches one term of the addition and throws
it into the accumulator which first must be emptied and therefore con-
tains the figure zero. The second operation command does the same thing
with the second term so that the sum of both terms is eventually in the
accumulator. Only the third operation, command will store the contents in
the desired memory and, at the same time, will empty the accumulator in
order to prepare it for the next operation. To exemplify: if the
figures 4.276 and 5.412 are stored in the registers 3 and 7 and register
11 is to receive the result, the program schedule of a three-address
machine is of the following structure:
1. Address Operation 2. Address 3. Address
7 11
whereas the program schedule of a mono-address machine appears in thisvways
Address Operation
3 Throw figure from register into accumulator
7 Throw figure from register into accumulator
11 Throw figure from accumulator into register
e. After it was decided that the three-address system was to be used, a
very serious question remained to be solved, that of the life span of 1
the machine. Experience gained in all countries of the world,plus
independent experiments carXied out in the Zeiss fires, made it clear
that under normal conditions a relay will be able to make between ten
million and a hundred million connections. This figure is liable to
greatly limit the life span of the machine.
* Note, i.e.9 the number of a given "memory" (Speichterregister)
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Therefore, a way was sought and finally found.which allowed the number
of connections of one relAto increase almost without limit. An
experiment which took several months, has been carried out and has
resulted in over one billion connections under conditions as they pre-
vail in the machine. No limit for the duration of this experiment are
foreseeable.
f. For reasons of calculating safety,two machines were built at the same
time. They act as twin machines and chock.y-aach other miLU&I-1y after
every basic operation. However, they can also be operated as indivi-
dual machines*
g. While the machine works with a binary code system (dual versohluesselt),
the input and output equipment work with the decimal system in order to
have a reasonable relation between the preparatory and the evaluation
time on the one hand and the calculation time proffer on the other hand.
In order to make possible a very flexible program handling, particularly
in order to make variation calculations possible, the input of programs
and figures is done with the aid of $,tee . ?tie special purposes
served bg$ this machine require cyclic programs "in mehrfacher Vsrschachts-
lung". "andling of such programs was-made possible through adding a
fourth address which permits conditional and unconditional jumps in the
sequence of operations and through an additional register (Speicher)
which works cyclically. In order to o.over as Zarge range of fignroe
as possible, sami4iogarithmio repsesentation (- a?10 ) was chosen
whereby b is confined to tie range of -15 to +15 and 'a' is an eight-
digit number with the comma after the first digit. This number must
have such a form that the digit preceding the comma is different from
zero. Results are given in this form by the machine itself, i.e. they
are "normed" by the machine. The figures "zero", "infinite" without sign
and "undetermined"-(or "imaginary") are introduced as special symbols.
Every decimal figure is represented by a four-digit number (Tetrad.)
of binary digits. Since the ten figures from 0 to 9 can be coded in
16 (24) combinations, the following code combinations were selected:
0 equals OOLL
5 equals WOO
1
equals
OLOO
6 equals LQOL
2
equals
OWL
7 equals LOLO
3
equals
OLIO
8 equals LOLL
4
equals
OLLL
9 equals LIDO
The advantage of this system lies in the fact that transit is easy from
any figure to the one which complements it to 9; this transit is done by
interchanging 0 And L. Thus subtractions can be easily changed into
additions.
h. A total of 32 possible operations are provided for. So far the following
ones have been selected:
1 to 16: Algebraic sums in such a form that the sums of the absolute
values of the terms can agso be obtained;
17: Multiplication;
18: Division;
19 to 20: Square root with positive or negative sign of the root;
21: Transfer from one register into another one;
22 to 24: Three special operations enabling the machine to make a de-
cision with regard to conditional usurps. 'The first operation
classifies all possible numbers (including zero, infinite and
undetermined) into one group containing all positive numbers,
and another one containing all other numbers. The second
operation olas-sifies them into one group containing only zero
and into another one containing all other numbers. The third
operation gives the same classification as the second one with
"infinite" being the only number in the first group;
25: Calculation terminated.
Literally in multiple insertions into one another,.
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is The results are printed. An electrical typewriter writes the results
in semi-logarithmic form (e.g. [phone] - o2 for +8.7042635 ? 10-2 -
0.087042635). The length of lines of writing can be adjusted. The
command desk has switch connections for either twin operation of the
machines or for individual operation. Colored lamps indicate whether
the calculation is carried out without disturbances. If,in a twin
operation,a red lamp is lighted,this means that the machines have
produced different results; the machines will then stop operations.
In such case, the input values, operations, addresses and results
can be re-read from lines of lamps for both machines. The last
operation which of necessity must include the error, can then be re-
peated.
3. The installation (i.e* both machines) has 17,000 relays and approximate-
ly 90,000 selenium rectifiers. The total wiring has a length of about
500 km. The number of welding spots is about one million. The install-
ation is fed with 6V and 127 current taken from a buffer battery which
is connected with the regular net. The required power is about 30 Watts
k. All relays are arranged in broad bands on the outside walls of the
installation whieh is 73 meters long. The wiring is well protected
inside the installation which can be entered through a door. An aisle
of 1.40 meters width and 2.40 meters height can be illuminated
through ceiling lamps.
1. Following are the calculation speeds which are eounted from the moment
when a command is accepted to the moment when the result is fed into
the registers
hlebraie additions about 120 milli-seconds
Multiplication s about ~00 milli-seconds
Division $ about 00 milli-seconds
Extraction of rootss about 1,200 milli-aeoonds
m. The machine has the capacity of 120 trained computers.
digital
specialist on computer development. I25X1
on his development of the 425X1
computer.
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