Tema D21 is the first book in the publication from the association of Datasaab's Vänner entitled ‘Bits & Bytes from Datasaab's history'. It describes the introduction of the D21 which marked Datasaab's entry into the field of commercial computing. It also describes how in the 1950's there was a dramatic increase in the need for computing power both in aircraft design and for on-board use. SARA, a successor to BESK was born, as well as the first transistorised computer — an embryo of airborne as well as commercial computers.
Bertil Knutsson, Sven Yngvell, and Kurt Widin describe how new technology in hardware and software was employed.
A modern production facility for electronic products was built.
It is shown how Saab gradually became aware of the commercial computer market, and Gunnar Lindström, Klas Küntzel, and Jan Annerstedt tell how the new D21 computer was applied to many exciting new ventures in the commercial field.
The book describes how customer support and maintenance was organised to meet the demands for high computer availability, and finishes with an historical survey of Datasaab between 1960 and 1990.