Texas Instruments

• Modern Desktop

Model: TI-5315
Battery: 
Adapter: AC 110 volt    
Year: 1989
Chip: NEC upd7520
Info: modern DESKTOP built in clock

• Slanted LCD

Model: TI-54
Battery: 2 x LR44
Adapter: 
Year: 1982
Chip:  CD4555,CD4551  
Info:  slanted LCD  generation

• Majestic line

Model: TI-55
Battery: BP 7
Adapter: AC9132
Year: 1979
Chip: TMC1503          
Info: TI-55 same as TI-51 III, but TI-55 was sold in the US while TI-51 III was sold in Europe.

• Slanted LCD

Model: TI-55 II
Battery: 2 x LR44
Adapter: 
Year: 1981
Chip:  CD4555,CD4556
Info:  slanted LCD  generation

• Slanted LCD

Model: TI-55 II programmable
Battery: 2 x LR44
Adapter: 
Year: 1984
Chip:  TP0456/CD4555, CD4556
Info: This TI-55 II could be called a rare calculator.