É«ºÐÖ±²¥

Until the information superhighway is constructed, motorcycle couriers will weave through the city streets with cargoes of Photo CDs and SyQuest cartridges. Unless, that is, the media industry finds a new removable storage format to satisfy its ever-growing need to transport megabytes from A to B.

A new cartridge format, designed specifically for multimedia, has just gone into production. The Multimedia Cartridge Drive combines hard-drive access times with the storage capacity of a CD-Rom. The cartridges are the size and shape of a 3.5 inch diskette, but a little thicker. Cartridges are expected to sell for around Pounds 40, far less than removable hard disk drives which offer similar performance but contain expensive read-write heads and actuator mechanisms.

MCD was developed by a consortium funded by the European Union's Esprit programme. The group comprises the French firm Nomai, its Scottish subsidiary Myrica, and the Olivetti-owned computer maker Acorn. Expertise in an advanced coding technology known as partial response maximum likelihood (PRML) was provided by the storage laboratory of the University of Plymouth. Another subcontractor was LETI, a French national laboratory located in Grenoble.

Nomai is now manufacturing MCD cartridges at its plant in Normandy. Other companies which may manufacture or distribute them are Maxell, Iomega and RPS. The drives are being built at Havant, Hampshire by Xyratex, a former IBM subsidiary which was bought out by its management.

Two versions of the drive have been developed. Already in production is a version with 540MB capacity, based on the thin film heads used in standard hard disk drives. This will be followed by a 680MB drive with magneto- resistive heads. The extra capacity is significant as it will enable the drive to copy an entire CD-Rom.

Major hazards are dust, dirt and misalignment, which could make one drive unable to read data recorded on another. The designers of MCD believe they have solved these problems.