WG&L incotax calculator (1983, 84) by Texas Instruments

Date of introduction:  1981 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:  4249533
Batteries:  BP1A Date of manufacture:  wk 05 year 1981
AC-Adapter:  AC9131 Origin of manufacture:  USA (ATA)
Precision:  13 Integrated circuits:  TMC0501E, TMC0580 (CD2400), TMC0580 (CD2401), TMC0573, TMC0591, Toshiba TC5047AP
Logic:  AOS - 8 Pending Operations, 9 ()    
Memories:  0-60    
Program steps:  480-0 Courtesy of:  Joerg Woerner

TI-58C_Incotax_2_BACK.jpg (546357 Byte)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.

The incotax application was developed by the Bureau of National Affairs, Inc., Washington D.C. to calculate Federal Income Taxes and distributed by Warren, Gorham & Lamont, Valhalla NY (WG&L).

Dismantling the tax planner calculator reveals a standard TI-58C calculator manufactured in February 1981.

Don't miss the 82' edition of the WG&L incotax calculator and the WG&L incotax 1985 calculator sporting an external program 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, February 8, 2010. No reprints without written permission.