In message <Pine.SO4.4.01.9810151054120.9430-100000@artemis>, Jon
Kerridge <[log in to unmask]> writes
>Transport and the Year 2000
>
>Perhaps the major problem for transport systems lies not in the major
>control systems that presumably traffic management authorities should
>already have dealt with or, more likely, they are only dealing with at
>the moment.
....
>In my opinion, the much more difficult problem to manage in the
>transport context is the use of the many outstations used in transport
>control systems that are located in street furniture. These
>outstations are very likely to use micro-controllers and small micro-
>processors many of which have a date and time capability. In many
>cases the data and time capability will not be used and it depends
>whether or not the date and time capability has been properly disabled
>as to whether there will be a Y2000 problem.
...
this disregards two far simpler questions which determine definitively
whether a device CAN be affected by date-awareness and Y2K.
The first question to ask is whether the device is powered by mains
electricity and, if so, whether it has a battery to carry the
electronics over a power failure. If the first answer is yes and the
second no, it is most unlikely that the device will be CAPABLE of date-
awareness or any symptoms of it. Simply, a power cut will remove power
from the device and will cause all memory and internal registers to
reset to zero (or random values). Any values in a 'date / time chip'
will therefore be lost every time the power goes off.
This of course only remains true if the timer chip DOES NOT have an
internal battery - as is the case with a PC. But then - why would a
designer of a 'Date Unaware' device include a battery-backed chip for no
purpose, when a cheaper chip would do the job?
--
John Brooks
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