Oprema -- The Relay Computer of Carl Zeiss Jena

TL;DR

The paper details the development, design, and application of the Oprema relay computer built in East Germany in the 1950s, highlighting its technical features and historical significance.

Contribution

It provides new insights into the Oprema project, including its architecture, operational details, and its place among early computers, emphasizing its role in German computing history.

Findings

Oprema was the 7th universal computer in Germany.

It used about 8,300 relays and 45,000 selenium rectifiers.

Operated from 1955 to 1963 in East Germany.

Abstract

The Oprema (Optikrechenmaschine = computer for optical calculations) was a relay computer whose development was initiated by Herbert Kortum and which was designed and built by a team under the leadership of Wilhelm Kaemmerer at Carl Zeiss Jena (CZJ) in 1954 and 1955. Basic experiments, design and construction of machine-1 were all done, partly concurrently, in the remarkably short time of about 14 months. Shortly after the electronic G 2 of Heinz Billing in Goettingen it was the 7th universal computer in Germany and the 1st in the GDR. The Oprema consisted of two identical machines. One machine consisted of about 8,300 relays, 45,000 selenium rectifiers and 250 km cable. The main reason for the construction of the Oprema was the computational needs of CZJ, which was the leading company for optics and precision mechanics in the GDR. During its lifetime (1955-1963) the Oprema was applied by CZJ and a number of other institutes and companies in the GDR. The paper presents new details of the Oprema project and of the arithmetic operations implemented in the Oprema. Additionally, it covers briefly the lives of the two protagonists, W. Kaemmerer and H. Kortum, and draws some comparisons with other early projects, namely Colossus, ASCC/Mark 1 and ENIAC. Finally, it discusses the question, whether Kortum is a German computer pioneer.