WG&L tax planner calculator by Texas Instruments

Date of introduction:  1982 Display technology:  LED-stick
New price:   Display size:  10 (8 + 2)
Size:  6.4" x 3.2" x 1.5"
 162 x 81 x 37 mm3
Weight:  8.5 ounces, 240 grams Serial No:  7676237
Batteries:  BP1A Date of manufacture:  wk 36 year 1981
AC-Adapter:  AC9131 Origin of manufacture:  USA (ATA)
Precision:  13 Integrated circuits:  TMC0501E, TMC0580 (CD2400), TMC0580 (CD2401), TMC0573, TMC0591, Toshiba TC5047AP
 TMC0540 (CD5704)
Logic:  AOS - 8 Pending Operations, 9 ()    
Memories:  0-60    
Program steps:  480-0 Courtesy of:  Joerg Woerner

The innovative TI-58 was the perfect base for a lot of customized calculators. The idea behind these products was the novelty of the Solid State Software Modules with up to 5000 program steps.

TI-58C-WGL_MIC.jpg (9053 Byte)TI-58C-WGL_Module.jpg (12039 Byte)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.

TI-58C-WGL_PCB.jpg (276696 Byte)Dismantling the tax planner calculator reveals a standard TI-58C calculator manufactured in Summer 1981. It is one of the earlier models, the printed circuit board (PCB) of the calculator was manufactured in Canada.

Compare the WG&L tax planner with a similar product by the insurance companies Agrippina, Allianz, Lloyd, LVM, Nordstern and Victoria or the Bossard screwing joint calculator. Even the French carmaker Chrysler-Simca used the TI-58, don't miss the Chrysler Credicavia. Don't miss the USMC HARRIER flight computer based on the TI-58 calculator, too.

A colorful calculator appeared with the Pool Water Analysis module.


Warren, Gorham & Lamont, Valhalla NY was founded in the 1950s, but traces its roots back to 1882, when Willard Warren started a weekly, the Connecticut Real Estate Record and Building News (later and still today, The Commercial Record). The Thomson Corporation acquired Warren, Gorham & Lamont (WG&L) in 1980. For more than three decades, WG&L was a major information source for finance professionals in companies of all sizes and industries. The WG&L product line includes some of the most valued newsletters, journals and treatises in the legal, tax and accounting fields. WG&L remains one of the most respected brands in the industry. In 1996, the tax publishing activities of Warren, Gorham & Lamont were merged with RIA.

WG&L is a trademark of Warren, Gorham & Lamont, Valhalla NY.

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If you have additions to the above article please email:

Joerg Woerner, May 7, 2008. No reprints without written permission.