Reid’s For Fun


My personal blog for what interests this computer guy. Web development, LEGO ray tracing, ZX81 retro computing, writing and photography.

Crafting Black Hole Graphics on the ZX81

Black Hole, ZX81 Screenshot 3, 2023 by Steven Reid

I had forgotten about this Black Hole program until I ran across it while cleaning up some directories. It is a conversion, not an original, program that was shared on one of my BASIC forums. It doesn’t look quite as good as the original, but it was interesting to see what the ZX81 could do with its simplistic graphics.


ZX81 Aquarium Makeover—Revamping Kimmie Fish in Assembly

Aquarium Screenshot 1, 2024 by Steven Reid

While on vacation, I spent some relaxing time converting my Kimmie Fish BASIC program into something a bit more interesting. In addition to the normal speed improvements, I wanted to give it an aquarium like feeling with bubbles and depth. No color here, this is all stock ZX81 graphics. Only thing needed is the requisite 16K memory pack.




Using Generative AI to Create Lunar Equestrian Dreams

Moon horse. AI Generated image, 2023 by Steven Reid

Funny enough, I'm still having a surplus of fun creating AI art. Between challenges and random ideas, it's been quite a year. I love reading articles and seeing what other creative minds come up with. Reading "This AI Tool Combines Stable Diffusion's Level of Control and Midjourney's Image Quality — It's Called Distillery," by Jim Clyde Monge, I was intrigued by some of his images and thought I'd give it a whirl with my own whimsical prompt.



Beyond the Atari: A Pitfall! Simulator for the ZX81

Pitfall! Simulator, ZX81 Screenshot of the Starting Room, 2023 by Steven Reid

While contemplating what ZX81 program to write about this month, I completely forgot that I had created a Pitfall! Simulator. It began as a fun project to occupy my time during winter break. My initial goal was to recreate David Crane's LSFR (Linear Feedback Shift Register) in Z80. However, after learning more about its functionality, I took the project much further than I had originally intended.


A Trip Down Memory Lane: Recreating “I Was Here” in ZX81 BASIC

Here, ZX81 screenshot, 2023 by Steven Reid

A recently posted meme reminded me of the silly things we did on computers. In the early eighties, most computers came with BASIC as their default OS. A common starting point was a s simple “hello world” program. But almost as often, someone wrote something a bit more personal. This is my tribute program to the “I was here” concept of those days.


How to Create an Infinite Maze on the ZX81

Infinite Maze, ZX81 Screenshot, 2023 by Steven Reid

I saw the Commodore 64 maze generator for years, but ignored it on my ZX81 for different reasons. For one, the characters needed didn’t exist on the ZX81 keyboard. The other was the lack of automatic scroll. Undeterred this month, I created my own version in Sinclair BASIC. I’m quite happy with the results, even if not quite the same.