TI professionalModel: TI Professional Koh-I-Noor
Battery: 9 volt or RK2
Adapter: AC9900/r
Year: 1978
Chip:  TMS0981
Info:  Made in Italy (RIETI) RCI

 It is obvious that the model professional - manufactured for Koh-I-Noor Hardtmuth - is a hybrid of three different products:

• The basic functionality is borrowed without any doubts from the TI-30 introduced in 1976
• The double-shot injection molded keys are known from the Business Analyst-I
• The yellow-brown keyboard plate is... unique

Dismantling this model professional manufactured in 1978 reveals a standard TI-30 printed circuit board (PCB) with the well-known TMS0981 single-chip calculator circuit.