avstar piperModel: Avstar Piper
Battery: 2 x LR43
Year: 1981
Chip:  TPO328
This Piper "Flight Computer" gives you an example of using existing products like the TI-35 for other purposes. We know similar approaches from the insurance business (view the TI-58 manufactured for Lloyd) but this one uses a specialized integrated circuit to perform different computations and conversions:

 Alt/AS: Calibrated, True Airspeed, Pressure, Density Altitude
 WIND: Wind Speed, Direction, Course and Heading 
 TSD: Time-Speed-Distance, Distance and fuel consumption
 CMP: Computes in the above modes the different values
CNV: Convert between US and SI-units
 T: Time calculations

BA real estateModel: BA real estate
Battery: 2 x LR44
Year: 1993
Chip:  T6m51 Toshiba
Info: modern LCD  1991 - 1999




BA 0020Model: BA-20
Battery: LR41
Year: 1997
Chip: Inventa LI3163
Info: Malysia




BA 35Model: BA-35 student business analyst 
Battery: 2 x LR44
Year: 1981
Chip:  CD4571
Info:  modern LCD  1982 - 1987





BA 45Model: BA-45 mcro business manager
Battery: 4 x AAA                
Year: 1984
Chip: nec UPD7503
Info:  later HANDHELD printing   made in Japan scientific