TI 2500 longinesModel: TI-2500 Longines Symphonette
Battery: 6 x AA ni-cd internal
Adapter: AC9100
Year: 1972
Chip: TMS0119
Info: 
This calculator sold by Longines Symphonette could be easily recognized as a Texas Instruments Datamath calculator. It followed the Electronic Calculator introduced few month earlier. The main differences between the original and the badged calculators are the olive-green colour of the housing, the grey keys and the Longines Symphonette label.