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Computer Date Stamp Control

IP.com Disclosure Number: IPCOM000048745D
Original Publication Date: 1982-Mar-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Bradley, CT: AUTHOR

Abstract

A computer instruction for adjusting a date timer is described. The date timer is adjusted without introducing sequence errors in the time stamp applied to jobs being processed by the computer. Adjustment without sequence error is accomplished by incrementing the timer at a slower rate or inhibiting incrementing when the timer is to be adjusted because it is running too fast. By not setting the timer back, time values plased in sequence fields of programs being run before and after correcting the time will not erroneously imply a wrong sequence.

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Computer Date Stamp Control

A computer instruction for adjusting a date timer is described. The date timer is adjusted without introducing sequence errors in the time stamp applied to jobs being processed by the computer. Adjustment without sequence error is accomplished by incrementing the timer at a slower rate or inhibiting incrementing when the timer is to be adjusted because it is running too fast. By not setting the timer back, time values plased in sequence fields of programs being run before and after correcting the time will not erroneously imply a wrong sequence.

The timer comprises a 19-byte memory area storing the year, month, day, hour, minute, and second. Microinstructions increment the contents of this field on a periodic basis, such as whenever the frame character of a communication loop being used as the time base is received. Use of an already existing communication loop as the time base provides a timer at no increase in cost but at a sacrifice of accuracy, such as perhaps a few seconds a day. To read or write the date and time of day, another 19-byte field is defined by the programmer to hold the new time to which the timer is to be set or to receive the time when a read timer instruction is being executed. A 3-byte field is used when the timer is to be adjusted. The first byte contains an A in order to advance the timer or a D in order to delay the timer. The next two bytes contain a number from zero through 99, indicating the number of secon...