Browse Prior Art Database

Entry Playback Function for Hand Held Calculators

IP.com Disclosure Number: IPCOM000086278D
Original Publication Date: 1976-Aug-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Desilets, BH: AUTHOR [+2]

Abstract

In this apparatus, input data entries to a hand-held calculator are stored and made available for display, for verification and/or correction.

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Entry Playback Function for Hand Held Calculators

In this apparatus, input data entries to a hand-held calculator are stored and made available for display, for verification and/or correction.

The conventional inexpensive hand-held calculator is normally not equipped with a printout means. Although information put into the calculator can be checked on the display as it is entered, there is normally no provision made for later verifying the information. A printing attachment suitable for accomplishing this function is a relatively expensive addition and is, therefore, not normally provided in inexpensive calculators. However, it may be desirable at the termination, or at an intermediate stage, to go back and check the input.

The subject concept can be implemented in a hand-held calculator by the addition of a little logic to a basic ALU, a first in/first out (FIFO) register stack and two additional keys to the keyboard, an error checking key and an entry playback key. The calculator can be provided with a store playback feature, plus the additional feature of permitting incorrect entries to be corrected as they are found. The correction feature is intended for use only when all operations in the calculation are associative. To correct the misentry, the user needs only to enter the correct entry, plus two function keys, one to cancel the results of the error and the other to enter the correct calculation.

Fig. 1 shows the main components of the calculator. Entries...