VERSION 1.0 19 June 1992 Version 1.1 26 June 1992 Version 1.2 21 October 1992: Add multiple blocks per page option. Version 1.3 15 November 1992: First Distribution. Version 1.4 6 December 1992: Add Colour commands. Version 1.4.1 1 February 1993: Small bug fixes - FULL RELEASE VERSION. Version 1.4.2 15 February 1993: Make silent_mode toggle. Version 1.4.3 1 March 1993: Fix bug in colour option. Version 1.4.4 24 March 1993: Add mask features (should be version 1.5). Version 1.4.5 25 May 1993: Include alsnum program in distribution. 7 June 1993: Fix NO_NUMBERS bug in documentation Change defaults for -q option to use MASK. Version 2.0 23 May 1995: Numerous changes and additions including the option to colour backgrounds differently, ommission of idents on second and subsequent lines, helix, strand and other special characters, relative numbering, error checking of ranges on input, bounding box, screening, conservation colouring... Version 2.03 5 June 1996: Small bug fixes - patches incorporated. BACKGROUND_REGION and BOUNDING_BOX commands moved to step 1 section.