BBC Domesday Project - Format

Format

The project was stored on adapted laserdiscs in the LaserVision Read Only Memory (LV-ROM) format, which contained not only analogue video and still pictures, but also digital data, with 300 MB of storage space on each side of the disc. Data and images were selected and collated by the BBC Domesday project based in Bilton House in West Ealing. Pre-mastering of data was carried out on a VAX-11/750 mini-computer, assisted by a network of BBC micros. The discs were mastered, produced, and tested by Philips at their Eindhoven headquarters factory. Viewing the discs required an Acorn BBC Master expanded with a SCSI controller and an additional coprocessor controlled a Philips VP415 "Domesday Player", a specially produced laserdisc player. The user interface consisted of the BBC Master's keyboard and a trackball (known at the time as a trackerball). The software for the project was written in BCPL (a precursor to C), to make cross platform porting easier, although BCPL never attained the popularity that its early promise suggested it might.

The project was split over two laserdiscs:

• The Community Disc contained personal reflections on life in Britain and is navigated on a geographic map of Britain. The entire country was divided into blocks that were 4 km wide by 3 km long, based on Ordnance Survey grid references. Each block could contain up to 3 photographs and a number of short reflections on life in that area. Most, but not all, of the blocks are covered in this way. In addition more detailed maps of key urban areas and blocks of 40x30 km and regional views were captured, allowing "zoom-out" and "zoom-in" functions. The community disc was double sided, with a "Southern" and a "Northern" side, although country-wide data at the 40x30km level and above was on both sides.
• The National Disc contained more varied material, including data from the 1981 census, sets of professional photographs and virtual reality-like walkarounds shot for the project. Side 2 of the National disc contained video material. The material was stored in a hierarchy and some of it could be browsed by walking around a virtual art gallery, clicking on the pictures on the wall, or walking through doors in the gallery to enter the VR walkarounds. In addition a natural language search was provided via an English stemming and matching algorithm to a set of keywords.