This lot comprises an HP 20S Scientific Calculator, made in the USA by Hewlett-Packard, accompanied by its original owner's manual, and a Texas Instruments Converter Calculator, manufactured in the USA, along with its Quick Reference Guide. Produced in 1988 (HP 20S) and 1981 (TI Converter), the lot also includes supplementary material, such as the 'Calculator and Converter Handbook.' These items reflect the evolution of personal computing tools of their era.