MA3: Martin Rootes – Vol. 1 for the BBC Micro
Martin Rootes 2019:
The computer graphic programs that I created for Micro Arts were all made on a BBC Model B microcomputer. This computer had a very extensive set of graphic instructions as part of its BBC Basic programming language. These allowed the creation of various shapes and also allowed for the colour code to be applied using a logical operation. The ability to logically apply colour codes and switch colour palettes gave the ability to create animated sequences. Without this ability the drawing processes itself would have been visible due to the speed of the processor (2 MHz, but with a 1 MHz bus).
There were six different programs done for the Micro Arts magazine. Each one was loosely based on different genres of art.
Generated swirling patterns influenced by Vorticist art.This repeatedly drew triangles of different colours in spirals that slowly built up a pattern on the screen.
A similar program drew various shapes using a facility in BBC Basic that allowed you to fill the shapes with dotted patterns. This combined with the “logical” drawing modes created moiré effects and was reminiscent of Op Art paintings. Both of these were fairly simple and just created the images by repeatedly drawing shapes, albeit with various rules to define how those shapes were created.
The other three programs were animated patterns.
The simplest one was based on De Stijl style art, with a pattern that was constructed using a grid that used the “Golden Proportion” to define the size of the squares. These then changed colour in sequence which produced an effect of them spiraling into the distance. This effect was also used on art for the Sheffield band Plan 9’s video of “Red Tin Boxes”.
This was inspired by the card mosaics used in the Moscow Olympics where a section of the crowd held up different coloured cards to create mosaic images. Whilst the main program is in Basic it has an assembler routine to swap between two different screens in sections.
The most complex animation took as its inspiration the painting “Nude descending a staircase” by Marcel Duchamp. This was based on an Eadweard Muybridge series of photographs, but instead of a nude descending a staircase it was of a running man.
To create this, the location each major joint on the man was traced and then transferred to graph paper to work out its co-ordinates. Once this was done they were used to create the image of the man but using triangles for the body and head and lines for the limbs.
Initially multiple copies of this image were drawn over the screen in different colours to create a patterned backdrop. This was then followed by sequences where the man ran from one side of the screen to the other, then each stage of the image was left on the screen creating a trail. This was recorded onto video at a later date with a sound track created using some rhythm backing tapes.
The following images are old screen photos as the programs are mislaid.