Exactra
Model: Exactra 19
Battery: 3 x AA
Adapter:
Year: 1974
Chip: TMC0806
Manual: with permission www.datamath.org
Info: When The Ohio State University approached Texas Instruments early in Summer 1974 with the demand of Thousands of high quality calculators in the $15.00 to $20.00 range for a Classroom Experiment, they actually initiated the development of this Exactra 19.
Model: Exactra 20
Battery: 3 x AA
Adapter:
Year: 1974
Chip: TMC0135
Manual: with permission www.datamath.org
Info: Texas Instruments introduced early in 1974 the Exactra line of calculators with the handheld models Exactra 20, Exactra 21, Exactra 22 and Exactra 23. The line was complemented with one desktop calculator named Exactra 31. The Exactra calculators do not use the name of the manufacturer on their nameplates, you have to read the small printed on the reverse to locate the Texas Instruments logo. The reasons are not clear, let us assume that in the middle of the decline of the calculator prices the marketing guys tried to establish a low-budget line.
Model: Exactra 23
Battery: 3 x AA
Adapter: AC9160
Year: 1975
Chip: TMC0803
Manual: with permission www.datamath.org
Info: The Exactra 23 could be called the fully loaded model in the cheap Exactra line. It sports an 8-digit display, a %-key and a connector for an external power supply.