Texas Instruments
Model: SR-16
Battery: 3 x AA ni-cd
Adapter: AC9200
Year: 1975
Chip: TMC1001
Manual: with permission www.datamath.org
Info: TIP line - classic first GENERATION
Model: SR-20
Battery:
Adapter: AC 110 volt
Year: 1973
Chip: TMS02020, TMS0304
Manual: with permission www.datamath.org
Info: DESKTOP line
Model: SR-22
Battery: no
Adapter: AC9222
Year: 1974
Chip: TMS0207, TMC0323, TMC0404
Info: Look carefully at the display of the SR-22 and you'll notice immediately that this calculator could perform amazing calculations. It is the only calculator reported so far to perform Octal-Decimal-Hexadecimal conversions on the base of floating point numbers.
Model: SR-40
Battery: BP 5
Adapter: AC9132
Year: 1976
Chip: TMC0981
Manual: with permission www.datamath.org
Info: MAJESTIC line