if the year is stored as four BCD digits in two adjacent bytes
and when comparing, you ignore the first two digits completely
and compare only the last two digits (which is valid until 99).
But the ill-fated programmer thougth the byte contained the
last two digits of the year in binary, but in fact it was BCD
(which is the same from 00 to 09, but 10 is different from 0a).
Kind regards
Bernd
Donald Johnson schrieb:
I'm not sure I follow how the BCD coding could cause this...maybe I am just
having a dense period today, but could someone give me an example of how
logic could see 2010 as 2016?
Thanks!
Don
On Fri, Jan 8, 2010 at 5:00 AM, Bernd Oppolzer
<[email protected]>wrote:
This is true. 30 million cards have the chip with the logic error on it.
It seems as if the BCD representation of the year 2010 is unterstood
by the card logic as 2016, and so the card is treated as not valid any
more,
but this is only a wild guess.
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