-----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Andy Wood Sent: Monday, May 21, 2007 2:29 PM To: IBM-MAIN@BAMA.UA.EDU Subject: Re: Synchronize Time Between Mainframe and Servers?
On Mon, 21 May 2007 09:55:13 -0400, Thompson, Steve <[EMAIL PROTECTED]> wrote: . . . > >Second, you most certainly can use an external time source to set the >mainframe (either via Unix System Services & TCP/IP, or through the HMC >-- neither of which I have personal experience doing). The question is, >since the time source you will attempt to sync to (absent an ETR >connected to a "GPS/UTC" time source) is NOT sufficiently accurate to >avoid ambiguities in TOD processing -- why would you desire to use NTP >to set the mainframe, as opposed to letting the mainframe be your NTP >source? This was my reason for pointing out, from the PoOP, that the >TOD cycles bit 51 at the micro-second rate, giving a very small drift . . . The magnetron in my microwave oven cycles at a sub-nanosecond rate. That does not mean it would be be suitable as a low drift clock source. <snip> Would that be because it does not have any missing-beat detection micro-code (no pun intended) and would as a result post an error condition (machine check)? Perhaps there is no circuitry to force the magnetron to lock at a precise frequency (say 1.037 GHz +/- 10KHz) because the freq drift is (a) not important as long as you stay around the "assigned" micro-wave freq +/- 1% so that leakage is not a problem? (b) H2O doesn't necessarily care about the precise frequency, close enough will do? (c) the FCC (or equivalent) doesn't care as long as there is insufficient leakage to interfere with other SHF devices? Sorry, but I've retired from working on radar and micro-wave stuff and haven't touched it since solid state took over. Regards, Steve Thompson -- Std. Disclaimer about employer, opinions, etc. -- ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
