Creative Graphics

for the BBC Microcomputer Models A and B

Computer art is now becoming more readily available with the superb graphics facilities offered by the BBC Micro - don't miss this chance to exploit them to the full. The pack contains 36 graphics programs on cassette which will run on either the Model A or B to produce a dazzling range of pictures including animated pictures, recursively-defined curves, and rotating three-dimensional shapes.

A full discussion of the principles involved plus program listings are given in the book “Creative Graphics on the BBC Microcomputer' (available separately). You will be amazed to discover just how easy it is to produce really intricate designs, and will quickly learn how to design your own spectacular graphics programs.

Running programs on the Model A

The programs on this cassette are supplied as versions that take advantage of the high-resolution graphics capabilities of the BBC Microcomputer Model B. Although on the Model A there will be lower resolution and fewer colours, Model A users will lose very little in terms of overall effect. The following instructions show how to alter the programs so they will run on the Model A.

All but two of the programs (FIELD and ISLAND) will run on the Model A if the MODE statement at the beginning of the program is changed to MODE 5. The procedure is as follows:

1. To load programs from cassette use the LOAD command instead of CHAIN. So to load the program MOUNTS, for example, type:
   
   LOAD "MOUNTS"
2. When the program has been loaded, escape from it by pressing BREAK.
3. Now type OLD followed by
   
   LIST 10,40
   
   which will list lines 10 to 40 inclusive.
4. Find the MODE statement at line 20, or line 30 of the program. It will probably read:
   
   20 MODE1
   
   All you have to do to change it is enter (next to the prompt)
   
   20 MODE5
   
   and press RETURN. Now when you LIST the program you will see that line 20 reads 'MODE5'.
5. To run the program, type RUN.

Modifications for FIELD and ISLAND

FIELD and ISLAND require further modification as listed below.

FIELD
Change line 20 to read MODE5.
Change line 150 to read VDU 28,0,9,19,0
Change line 190 to read VDU 28,0,9,19,0
Change line 350 to read VDU 28,0,31,19,10

ISLAND
Change line 20 to read MODE5.
Delete lines 90 and 150 from the program. The way to do this is to type at the end of the listing:

90 (RETURN)
150 (RETURN)

When you LIST the program you will see that lines 90 and 150 have been deleted.

PROCSURF, the procedure giving the effect of white surf on the waves, will not operate on the Model A.

Loading

To load and run the programs type, for example

CHAIN "MOUNTS"

Each program will take less than one minute to load.

Refer to the manual 'Creative Graphics on the BBC Microcomputer' (available separately) for full details of the programs on this cassette.

Contents

SIDE A

SIDE B

Game Credits

Author: John Cownie

Acornsoft Limited, 4a Market Hill, Cambridge, CB2 3NJ, England. Telephone (0223) 316039

SBX01