Browse Prior Art Database

Microprocessor for a Perpetual Calendar Display

IP.com Disclosure Number: IPCOM000084819D
Original Publication Date: 1976-Jan-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Ying, E: AUTHOR

Abstract

Described is a perpetual calendar that can display the month of any year (B.C. or A.D.). The calendar displayed may be Gregorian or Julian.

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Microprocessor for a Perpetual Calendar Display

Described is a perpetual calendar that can display the month of any year (B.C. or A.D.). The calendar displayed may be Gregorian or Julian.

The general concept is depicted by the block diagram of Fig. 1. Where: Y is the requested year (-Infinity < y < Infinity). M is the requested month (1 </= M </= 12 ). C is the calendar mode (Gregorian or Julian). N is standard year (0 </= N </= 13 ). L is standard month (0 </= L </= 27 ).

The Display logic circuit provides a visual display of the calendar month.

Fig. 2 depicts a flow chart of the microprogram employed. The microprogram transforms the requested year Y (-Infinity < y < Infinity ) into a standard year N (0 </= N </= 13). It takes into account the irregularities inherent in the Julian calendar, the Gregorian calendar, as well as the intervening leap years. It provides a standard year signal N (</- = N </- = 13) to the matrix logic circuit.

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