Some cities have learned the hard way that these machines must be upgraded regularly, essentially playing an arms race with vandals.

But as machines were upgraded, the school began to notice problems.

The machine is upgraded to allow for more data throughput and a time range of about 24 hours.

Tufting machines are being upgraded with modular needles.

Older machines can be upgraded to include more appropriate forming sections.

The machine has since been upgraded to produce slightly more energetic, brighter beams.

The machines have been gradually upgraded, but they are no match for the most skilled human cutters.

Eight machines per year should be upgraded from April 1993 onwards.

The full potential of the range is such that the new machine could be upgraded to up to 250 per cent of its initial capacity.

This allows non-networked machines to be upgraded.