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- From: mhemy+@cs.cmu.edu (Michael Hemy)
- Newsgroups: comp.sys.ibm.pc.hardware
- Subject: Clock glitch or...virus?
- Message-ID: <C0pFy0.Lsx.1@cs.cmu.edu>
- Date: 11 Jan 93 19:39:29 GMT
- Article-I.D.: cs.C0pFy0.Lsx.1
- Sender: news@cs.cmu.edu (Usenet News System)
- Organization: School of Computer Science, Carnegie Mellon
- Lines: 22
- Nntp-Posting-Host: n2.sp.cs.cmu.edu
-
- Yesterday when using my computer, I noticed that the time was wrong.
- It was not wrong by 1 or 2 seconds but by a FULL HOUR ! I checked the
- RTC (real-time clock) and it was correct. So I began wondering what made the
- DOS time SO different. This was extremely peculiar since you usually
- expect the DOS time to LAG after the real-time clock, and here I had
- it AHEAD of it.
-
- My first reaction was that there might be a virus lurking in my
- computer but after thinking about it some more, I came with the following
- theory:
-
- Since DOS is getting it's time initially from the RTC at boot-time, it
- may be that it is doing so in two (or more) stages, such that first it
- reads the minutes and then the hours. If this is true and I turned my
- computer on at 11:59 pm, then it may have read 59 minutes and when it
- got to read the hours it was 00 (am) already, so that it thought the
- time was 00:59 am.
-
- Can someone that knows DOS internals, shed some light on this or...
- can some virus expert say something about that phenomenon ?
-
- --Michael
-