WG&L incotax (1981,82) calculator 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:  1002659
Batteries:  BP1A Date of manufacture:  wk 29 year 1980
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-58C 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).

The different programs of the incotax application used various overlays to the already modified calculator keyboard of the TI-58C.

Don't miss the 84' 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.

horizontal rule

If you have additions to the above article please email:

Joerg Woerner, November 20, 2013. No reprints without written permission.