What is the Accuracy of VAX the Time of Year (TOY) Clock?
The VAX Time-Of-Year (TOY) clock (used to save the time over a reboot or power failure) is specified as having an accuracy of 0.0025%. This is a drift of roughly 65 seconds per month. The VAX Interval Time is used to keep the running time, and this has a specified accuracy of .01%. This is a drift of approximately 8.64 seconds per day. Any high-IPL activity can interfere with the IPL 22 or IPL 24 (this depends on the VAX implementation) clock interrupts—activities such as extensive device driver interrupts or memory errors are known to slow the clock. Also see Section 14.8, Section 4.2.
The VAX Time-Of-Year (TOY) clock (used to save the time over a reboot or power failure) is specified as having an accuracy of 0.0025%. This is a drift of roughly 65 seconds per month. The VAX Interval Time is used to keep the running time, and this has a specified accuracy of .01%. This is a drift of approximately 8.64 seconds per day. Any high-IPL activity can interfere with the IPL 22 or IPL 24 (this depends on the VAX implementation) clock interrupts-activities such as extensive device driver interrupts or memory errors are known to slow the clock. 14-30 Hardware Information Also see Section 14.8, Section 4.3.
