BBC : 'Embedded systems
In the case of air traffic control it is easy to identify which computers are involved, and
then set to work re-coding the date systems to introduce them to the idea of a new
millennium. Unfortunately that is not always the case. Computer chips have found their
way into everything from cars to kettles. Modern buildings are crammed with built-in
processors (called embedded systems) that control lifts, lighting, heating, sprinklers, and
security. Much heavy machinery is reliant on chips that monitor and control activity, and
keep tabs on when the machine is due for maintenance. In many cases, for safety
reasons, those chips will shut down any machinery in the case of anything unusual.
Chips in embedded systems are usually venerable classics of computing. On the
desktop we may demand the latest and fastest, but in embedded systems, where
simplicity and reliability is more important than speed, tried and trusted technology wins
out every time. Most satellites, and the Mars Pathfinder, are using a Z-80 chip originally
sold in the '70s and virtually identical to that used in the first Sinclair home computers.
They're cheap, they have a proven track record, and the tools for programming them
are widely available. The humble 286 processor that powered PCs back in the late
'80s is now to be found in many plumbing, and air conditioning systems, watching over
the flow of fluids and the operation of valves. The problem is that these chips, and the
software running on them, are not usually aware of the year 2000. As the party hits its
peak, a lot of heating and lighting systems will simultaneously take a huge step back in
time.
What happens varies from one case to the next. Where the operation of the machine is
not date dependent, they will simply carry on. Where they are day dependent, such as
offices that switch off the lights at weekends, they will be out of synch. But where they
control dates for safety there may be more serious problems. Many will be confused,
and will shut down automatically. An embedded systems consultant for the Cara
Corporation was recently asked to brief US congressmen on the issue, he had little
comfort to offer. "Every test I have seen done on an electrical power plant has caused it
to shut down. Period. I know of no plant or facility investigated to this date that has
passed without Y2K problems," he said. Whilst you might want to have some candles
ready at that party, it should be remembered that the electricity companies are aware of
the problem, and working on averting it. The danger lies not so much in the spectacular
(and thereby obvious) sources for failure, but in the ones we overlook.
Embedded systems watch over the danger thresholds in nuclear power plants, they
keep life support systems ticking over in hospitals, they change the traffic lights from red
to green, they keep production lines rolling. All of those systems must be made Y2K
compliant, either by updating them, or by replacing them. While work is underway with
most of the critical ones, where life truly depends on them, the scale of the problem
means that some embedded systems will not be updated on time, and a certain amount
of disruption seems inevitable.
bbc.co.uk |
