Paul Gilmartin wrote:
On Tue, 4 Sep 2007 17:19:27 -0400, Art Celestini wrote:
I don't know about any clock simulators, Ed, but I went and found the code
that was involved and it was the CONVTOD macro that accepted a maximum date
of September 17, 2042. Ed Jaffe pointed out that the hardware does not yet
support higher dates, but I might argue that the software (CONVTOD) still
could, at least when using the STCKE/ETOD format.
Could. But how much foresight did systems show in anticipating Y2K?
Would you expect preparation for Y2.042K 35 years in advance? And
do we know how the hardware will employ the higher bits in the future?
Ummm. For about the last decade, POP has stated the following:
At some time in the future, new models will use a carry from bit
position 0 of the TOD clock to increment an additional eight-bit
binary counter. STORE CLOCK EXTENDED will store the contents of this
counter in byte position 0 of its storage operand. A variation of SET
CLOCK will set the counter, as well as the TOD clock. Variations of
SET CLOCK COMPARATOR and STORE CLOCK COMPARATOR will manipulate a
comparable byte at the left of the clock comparator. These actions
will allow the TOD clock to continue to measure time within the
standard epoch after the current 143-year limit caused by a carry from
bit position 0 has been exceeded, and they will allow continued use of
the clock comparator. It may be desired to have programs that process
16-byte STORE CLOCK EXTENDED operands take these future developments
into account.
--
Edward E Jaffe
Phoenix Software International, Inc
5200 W Century Blvd, Suite 800
Los Angeles, CA 90045
310-338-0400 x318
[EMAIL PROTECTED]
http://www.phoenixsoftware.com/
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