This pack consists of a set of graphics routines on cassette which can be incorporated into programs to present data graphically in a wide range of applications. Included are two-dimensional graphs, three-dimensional graphs, stereo pairs, two-dimensional contour maps, three-dimensional contour maps, bar charts and pie charts. Also included are programs which can be run on their own to design graphs interactively from the keyboard.

The programs will prove invaluable for presentation of statistical or business data of all kinds, and to researchers and report writers who wish to use illustrative material as an aid to comprehension. For teachers, the package contains a wealth of mathematical teaching material and demonstrates some of the excellent graphics capabilities provided by the Acorn Electron.

Complete listings and details of how to use these programs are given in the manual Graphs and Charts on the BBC Microcomputer (available separately); this manual is essential reading for users of the Graphs And Charts cassette.

Level 3 programs (prefixed L3-) can be loaded and run in the usual way. For example, to load and run the program L3-BAR, place the cassette (fully rewound) in the cassette recorder, type

   CHAIN "L3-BAR"

and press RETURN; the 'Searching' message should appear on the screen as you do this. Now press the PLAY button on the cassette recorder and wait for the program to load.

Programs in Levels 1 and 2 are designed to be incorporated into your own programs, and so are in EXEC format. All Level 2 programs and some Level 1 programs require either L1-2D or L1-3D, the fundamental plotting programs, to be loaded also - the appropriate program name appears in parentheses next to these program names. To load L2-HIS, for example, you would type:

   *EXEC "L2-HIS"

and press RETURN. Then press the PLAY button on the cassette recorder. The program is listed on the screen during loading. Once loaded, type:

   *EXEC "L1-2D"

and press RETURN. Press PLAY on your cassette recorder and wait for this program to be loaded in also. At this point you should refer to the book Graphs and Charts on the BBC Microcomputer for details of running these programs.