Faber-Castell
A. W. Faber-Castell Vertrieb GmbH
Stein, Germany

A.W. Faber-Castell, a German manufacturer of slide rules, introduced in the year 1973 the „TR1 Calculator Slide Rule“. One side of the housing featured an electronic calculator and the other side a traditional slide rule.

Source : Joerg Woerner, Datamath Calculator Museum