I’ve enjoyed playing with graphics since I was ten years old. My dad brought home a HP-85 computer from work which had a tape drive, a built-in thermal printer and a monochrone display. Very cool for 1981.

ten year old David programming HP-85 HP-85 graphics from the manual

I remember what a thrill it was to get a dot moving around the screen for the first time.

The manual had lots of interesting images in the Graphics chapters. I remember playing around with the maths functions to see what would happen (though I had no idea what cos or sin meant).

HP-85 line drawing HP-85 program listing

Just for fun, I wrote some HP-85 programs using an emulator a while ago. Here are some images.

HP-85 graphics examples

(The one on the bottom right was a gravity simulation. Two objects in the upper left corner wove in and out of each other’s path for a while).

When I was a teenager we got an Apple 2e, then an Apple 2gs. Full colour palette!

chaotic ribbon touching swords
embossed spiral effect contour map
lines of attraction sphere of cubes

There is an interactive version of the pink and purple attractor above (second last image above), written in JavaScript.

A few years ago I had a block of time between jobs, so I wrote some plugins for a C# program called Paint.NET. The largest one was called Curly Lines. It started off drawing lightning, and grew from there.

gold leaf sun embossed gold shapes
fractal lightning sea creature
flower petals cogs
grass and purple worms
spiked ball flames

I also made a plugin called Cell Texture:

cell texture spheres coloured crystals
electric cell texture coloured cells crystal surface

... and one called Stipple.

stippled face of Dr Janet Frasier


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