IBM PC Real Time Clock should run in UT , Computer Laboratory, University of Cambridge A plea to the developers in charge of the real-time clock driver in Microsoft operating systems. Background What is Universal Time? Universal Time (UT), also known as Greenwich Mean Time (GMT), is the astronomical local time on the prime meridian. Its atomic-clock representation, known as Coordinated Universal Time (UTC) and defined in ITU-R Recommendation TF.460-4, is the official international reference time scale, the basis all time announcement services and most national definitions of time. Universal Time is not affected by any national Daylight Saving Times. It has long become the global reference time in distributed computer systems and many other applications. What is the PCs Real Time Clock? Every IBM PC compatible computer features a battery-backed Real Time Clock (RTC) chip. This contains a 32768 Hz crystal oscillator that drives a date/time counter. It also contains 114 bytes of battery-backed CMOS RAM that are reserved for BIOS use. The chip typically used is compatible to the Dallas Semiconductor DS1287 and Motorola MC146818B RTCs. How does MS-DOS relate to this? The original IBM PC was released with the first Microsoft DOS and Basic versions in the early 1980s. At that ...
