Texas Instruments

• overhead

Model: TI-10 overhead
Battery: 
Adapter: 
Year:  2006
Chip: made in China
Info:  The California based company Stokes Publishing Company, Inc. distributes under the label "The Educator®"
calculators optimized for teaching purposes. William T. Stokes filed already July 30, 1991 the US Patent Application U.S. Pat. No. 5,035,502
 with the title "Transparent calculator for overhead projection".

• LCD-1982-1987

Model: TI-12 math explorer
Battery: solar
Adapter: 
Year: 1988
Chip:  T6m39s Toshiba
Info:  modern LCD  1982 - 1987

• LCD-1991-1999

Model: TI-12 math explorer
Battery: solar
Adapter: 
Year: 1998
Chip:  T6m39s Toshiba
Info:  China. The Math Explorer ( TI-12) is another calculator introduced by Texas Instruments to perform fractional arithmetic for elementary school. 

• overhead

Model: TI-12 intermediate overhead
Battery: 
Adapter: 
Year:  
Chip: made in China
Info:  The California based company Stokes Publishing Company, Inc. distributes under the label "The Educator®"
calculators optimized for teaching purposes. William T. Stokes filed already July 30, 1991 the US Patent Application U.S. Pat. No. 5,035,502
 with the title "Transparent calculator for overhead projection".

Model: TI-15 explorer lcd
Battery: CR2025
Adapter: 
Year: 2007
Chip: China
Info: