TI 0059 tax plannerModel: TI-59 WG&L Tax Planner
Battery: BP1 A
Adapter: AC9131 
Year: 1981
Chip:  TMC0501E TMC0591 CD2400 CD2401 TMC0573 TC5047         
Info: The tax planner application was developed in 1982 by Warren, Gorham & Lamont, Valhalla NY (WG&L) and programmed by Texas Instruments into a Solid State Software Module. Please notice the © 1983, 1984 date of the module. These modules were probably changed every year due to updates in the tax calculation process and WG&L introduced in 1985 with the incotax calculator a more flexible approach.