Editing BBC Domesday Project (section)

== Format ==
[[File:BBC Master AIV (Domesday System) (1).jpg|thumb|The Domesday System]]
[[File:Acorn 8-bit microcomputers (cropped) BBC Master AIV.jpg|thumb|BBC Master AIV]]
[[File:BBC Domesday machine keyboard.jpg|thumb|Function key strip for navigation]]
[[File:Philips VP415 (1).jpg|thumb|Philips VP415 LaserVision laserdisc player]]
The project was stored on adapted [[LaserDisc]]s in the [[LV-ROM|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. Initial estimates indicated a total storage capacity of 2 GB per disc, described as sufficient for 80,000 pictures (including satellite images) and "half a million text pages" plus software to process maps and graphical information.<ref name="acornuser198412" /> The delivered product was estimated to offer a "total potential capacity" of around 1400 MB with half of that capacity filled.<ref name="acornuser198707">{{ cite news | url=https://archive.org/details/AcornUser060-Jul87/page/n82/mode/1up | title=The Domesday Device | work=Acorn User | date=July 1987 | access-date=26 October 2020 | last1=Telford | first1=Joe | pages=81–83, 85 }}</ref>

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|VAX-11/750]] mini-computer, assisted by a network of BBC Micro microcomputers. The discs were mastered, produced, and tested by the Philips Laservision factory in Blackburn, England.

Viewing the discs required a BBC Master AIV - an Acorn [[BBC Master]] expanded with a [[SCSI]] controller and the 65C102 "Turbo" [[co-processor]]<ref name="acornuser198609">{{ cite news | url=https://archive.org/details/AcornUser050-Sep86/page/n8/mode/1up | title=Master to drive video disc | work=Acorn User | date=September 1986 | access-date=21 March 2021 | pages=7 }}</ref> - which controlled a Philips VP415 LaserVision laserdisc player. The user interface consisted of the BBC Master's keyboard and a [[trackball]] (more specifically the [[Marconi Company|Marconi]] RB2 Trackerball rebranded by Acorn).<ref name="acornuser198707" /> The enhancements provided by the Philips VP415 permitted computer control and access to data stored on the discs.<ref name="vp410">{{ cite web | url=https://www.domesday86.com/?page_id=1804 | title=Philips VP410 | website=Domesday86.com | access-date=30 November 2020 }}</ref>

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&nbsp;km wide by 3&nbsp;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, supported through the application of the [[Martin Porter|Porter]] stemming algorithm.<ref name="finney" />