Well, that's an interesting point you raise, Barry! On the one hand there is this 10-year old newfunction apar OW38015 : 128 bits TOD clock(Date Closed : 99/03/19): This APAR provides OS/390 MVS support for the new 128-bit extended TOD clock on S/390 Parallel Enterprise G5 servers and simulates support on earler servers. | oTOD-- Unsigned 64-bit binary number | oETOD -- Unsigned 128-bit binary number https://www-304.ibm.com/ibmlink/sis/viewAparDoc.wss?context=aparAndUsage&documentIds=OW38015&lc=en&cc=BE
On the one hand there is the actual z/Architecture with the TOD clock still being a 104-bit register: SA22-7832-07 zArchitecture Principles of Operation (PoP)(dz9zr007) (February 2009) http://publibz.boulder.ibm.com/epubs/pdf/dz9zr007.pdf page 4-37 The time-of-day (TOD) clock provides a high-resolution measure of real time suitable for the indication of date and time of day. The cycle of the clock is approximately 143 years. ... ... ... The TOD clock is a 104-bit register. It is a binary counter with the format shown in the following illustration. etc........... page 1-18 The extended-TOD-clock facility includes (1) an extension of the TOD clock from 64 bits to 104 bits, allowing greater resolution; (2) a TOD programmable register, which contains a TOD programmable field that can be used to identify the configuration providing a TOD-clock value in a sysplex; (3) the SET CLOCK PROGRAMMABLE FIELD instruction, for setting the TOD programmable field in the TOD programmable register; and (4) the STORE CLOCK EXTENDED instruction, which stores both the longer TOD-clock value and the TOD programmable field. STORE CLOCK EXTENDED can be used in the future when the TOD clock is further extended to contain time values that exceed the current year-2042 limit (when there is a carry out of the current bit 0 of the TOD clock). (August, 1998) Jan >----- Oorspronkelijk bericht ----- >Van : Barry Merrill [mailto:[email protected]] >Verzonden : donderdag , april 9, 2009 10:18 AM >Aan : [email protected] >Onderwerp : Re: "New" TOD (Was:Howard Turetzky has a NEW EMAIL ADDRESS) > >With regard to the 8-byte clock wrapping in 2042, >I believe that IBM has to resolve this issue >not later than 2011 or 2112, because tapes can >have a maximum retention period of 30 years. > > >Barry Merrill > >---------------------------------------------------------------------- >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 > > ---------------------------------------------------------------------- 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
