176 x 224 pixels, created using a Vic-20 computer.

I am very pleased with the range of colours achieved in this multicolour mode “Tone Paint” program image. The Auxiliary colour was set to be ‘mauve’. This one image shows that the Vic-20 can display some reasonable colour subtlety, though you need to blur your eyes a bit to combine the textures into resulting colours.

I added to my program, the ability to apply randomly coloured, sized and placed rectangles on the screen, and randomly coloured and placed single characters (or tiles) over the screen. I also added the ability to apply randomly placed and sized rectangles using a randomly chosen character, but using the character colour that was under the cursor at the time of applying those rectangles. I enjoyed developing these features in my program, as a result of playing with the program to try to create interesting abstract images, based on visual relationships.

I found it useful to add some machine code routines for storing and retrieving an undo image, which would allow me to revert to the state of the image before the last process was applied.

The image above is from a screen capture of a Vic-20 screen from WinVice 2.1. The Vic-20 computer however was designed to be connected to a colour TV, which would blur some of the detail of the patterns that have been captured here. To better show the colours that have been created using the various characters designed and used by my Vic-20 painting program, I wrote a separate Windows utility program that would take the captured images from WinVice 2.1, and convert each of the Vic-20’s screen of 22 x 28 coloured character patterns to a flat colour. It did this by averaging the colour of each pixel in each 8 x 8 pixel character design. The result for the image above is shown below. Hopefully, you can see how the patterns used for each Vic-20 ‘character’ have been evened out to flat rectangles of colour. I was very happy with the results from my utility program, which shows how well the Vic-20 can operate as a colour computer.

176 x 224 pixels, converted Vic-20 computer image, averaging the colour pixels for each screen character.

The subtle colour possibilities, as well as wide range of colour, of the Vic-20 computer can be better appreciated from this conversion.

176 x 224 pixels, created using a Vic-20 computer.

Another “Tone Paint” program image of pleasing colours.

176 x 224 pixels, converted Vic-20 computer image, averaging the colour pixels for each screen character.

The subtle colour possibilities of the Vic-20 computer can be better appreciated from this conversion.

176 x 224 pixels, created using a Vic-20 computer.

This certainly looks like an image from a colour computer.

176 x 224 pixels, converted Vic-20 computer image, averaging the colour pixels for each screen character.

The wide range of colour possibilities of the Vic-20 computer can be better appreciated from this conversion.

176 x 224 pixels, created using a Vic-20 computer.

I wanted to see if I could produce an image on my “Tone Paint” screen, by systematically scanning over the whole screen to see if I could determine a suitable character to paint each character block. It is a simple form of ray-tracing. I set up a mathematic definition of a circular ring, and used super-sampling of each character space (basically dividing each character space into 12 points to test) to determine the character to be used for each character space. It was an excellent programming challenge.

The results of these ray-traced images look like extreme close-ups of figures rendered on computer screens with antialiasing. If you imagine converting the image to greyscale where the red is changed to a mid grey, you should see quite good antialiasing.

These ray-traced images took several hours to produce the resulting images.

176 x 224 pixels, created using a Vic-20 computer.

The next challenge was to try to ray-trace an image of a square that had been rotated by a certain number of degrees.

176 x 224 pixels, created using a Vic-20 computer.

I programmed the rendering of this colour wheel using a similar method to the previous ray-traced images.

176 x 224 pixels, converted Vic-20 computer image, averaging the colour pixels for each screen character.

The subtle colour possibilities of the Vic-20 computer can be better appreciated from this conversion.

176 x 224 pixels, created using a Vic-20 computer.

I managed to load small sized (22 pixels x 28 pixels) 24-bit colour files into a free section of memory for reading into my “Tone Paint” program. The trick was to firstly work out all of the available colours that the Tone Paint program could produce (given specific screen, border and auxiliary colours), and use these to best match each colour read from the photograph. To work out the available colours of the Tone Paint program, I averaged the pixel values of each available combination of character colour with character patterns. This proved to be quite a task. I recorded the colour results in an array (if it was uniquely different to all of the other colours collected so far), along with the character colour and character pattern number.

I found that I could try a variety of strategies to match the colours, to see what resulted in the best reproduction. Unfortunately, I found that the whole process (including loading in programs and image data) took a long time for the Vic-20 (about 2 hours per photograph image)! Seeing the image that resulted was always exciting, probably because I knew how much processing (and time and care) was involved. I quickly realised that I shouldn’t expect a highly-detailed image.

Interestingly, I generally found the best results came from using a screen colour of light red, a border colour of black, and an auxiliary colour of light purple-blue. I am very happy with the results of the photographs I processed. I found these photographic images fascinating!

176 x 224 pixels, converted Vic-20 computer image, averaging the colour pixels for each screen character.

The subtle colour possibilities of the Vic-20 computer can be better appreciated from this conversion.

This changing display has been started by default. Images should change every 3 seconds or so. Click on the “Stop Sequence” button to stop the images from changing.

I think the range of graphics shown in this presentation shows that the Vic-20 computer was capable of creating some excellent and interesting images.

End of this presentation.

Return to Gallery 4.