LV-ROM.
Phillips
VP-415 Laserdisc player.
The Domesday project being such a large project consisting of a collection of text, photographs, data and even video clips required a mass storage medium as the floppy discs of the time simply could not hold this amount of data.
The Domesday project was conceived using technology available in 1983-1986. Mass storage systems such as CD-ROM were not readily available and the big optical format of the time was Laserdisc. Had CD-ROM been available it would still require a huge number of CD's to store all the images as no MPEG or JPEG compression was available at that time. The project management chose Laserdisc as the storage format due to the ability to hold many thousands of images as single video frames on a single disc.
Philips were approached because they produced the only videodisc players made in Europe. Philips suggested putting a data channel onto the disc in place of the usual sound channels. The data channel would provide over 300 Megabytes of data on a disc side. A special player was designed called an LV-ROM player that could extract the data from the new data channel and present it over a SCSI interface. The Phillips VP-415 Laserdisc player was the only player produced with the special SCSI interface. Other LV-ROM implementations were produced for other applications such as arcade machines, however only the VP-415 could be used for the Domesday project.
The LV-ROM concept was probably the best choice at the time but it has caused a few problems with conserving the information for the future. Not long after the Domesday project was completed CD-ROM became established as the de facto mass optical storage medium for computers and so very little further development went in to LV-ROM. With the advent of DVD even the standard Laserdisc for video has all but disappeared now.
The fact that the player was a one-off and only produced in small quantities has resulted in the players being quite rare. Spares to repair players are virtually non existent as no other player shared the components in the VP-415. Fortunately I have managed to obtain one working player and one partial working player.
As the pictures are analogue and the data held in a proprietary format it has not been possible simply to copy the information from one media format to another. A couple of projects have been attempting to conserve the data, one attempting to emulate the original system on a modern PC the other converting the data and implementing new software to read it on a modern PC.