SPI Tolerance 2

Edward A. Gardner 522-2247 02-Jun-1994 0759 gardner at ssag.enet.dec.com
Thu Jun 2 07:05:24 PDT 1994


Bill Galloway wrote:

>>3)  I agree that the correct reading of SPI today means a minimum of
>>    100.000000...ns not 99.99999999...ns.  I cannot negotiate for a
>>    period of 96ns because that is not defined in SCSI-2, and I doubt
>>    that many targets would agree to a period of 96ns.

Not to be overly pedantic, but 100.000... and 99.999... are
precisely the same value.  This is one of the "tricks" that first
year algebra instructors use to impress their students.  It has
several forms, one is:

       1/9   = 0.111...
     9*(1/9) = 0.999...
        1    = 0.999...

Nothing bogus here, they really are the same value.  Just one of
the properties of rational numbers expressed as (repeating)
decimal fractions.

Ed Gardner




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