After updating my print scroll routine, I started thinking about how I could use it to create a different version of my infinite maze program. The original used graphic characters and spaces since the ZX81 lacked a backslash. This new version takes a different approach, using alternate graphics to build a more visually interesting maze while leveraging a better machine scrolling routine.
I’d read about and studied cellular automata but had never programmed any simulations for them. Conway’s Game of Life is the go-to simulation and something others had already implemented on the ZX81, even when I was a kid. I finally got around to typing in some of those programs but found them slow. My version aims to correct that.
Another year and another Vintage Computing Christmas Challenge (VC3 for 2024). I rushed a bit to get mine in so I do feel it wasn’t as short as possible. I did take a somewhat unique route to solving the problem which makes the build more interesting. I made an auto-run version for Present so you could see it in action.
The year is almost over and time to close out the year with a short program. Watching some videos on character displays in UNIX, I was inspired to create my own version of Hello World. This version scrolls through a stream of random digits until the message is displayed. How fun is that?
Today marks the 40th anniversary of the 1984 Dune movie, a film that still holds a special place in my heart. Don’t get me wrong—I thoroughly enjoy Denis Villeneuve’s stunning adaptations, and I admire how he’s brought Frank Herbert’s world to life for a new generation. But for me, the original remains unique. It’s tied to so many of my childhood memories and the passions I cultivated during those years.
One thing I hadn’t done before on the ZX81 was hires graphics. There are numerous reasons, but in general it was because I hadn’t tried. That changed after being encouraged in my ZX81 group to use with with Mandelbrot Set program. So I did.
After wrapping up the last print scroll routine, I immediately dove into improving it. While functional, the original version felt a bit limited. With this update, you’ll find more flexibility in printing displays, though at a slight cost to speed.
As plans go, I actually have a few programs teed up to share. Many are smaller programs that I could work on here and there. Occasionally, I run across an idea that upends those plans and I end up going another direction. So, here we are in September with a math program for the Collatz Conjecture.
Sometimes, you do things out of necessity. I spent an inordinate amount of time working on adding automatic scrolling to a PRINT command. In fact, I haver another version of my print scroll routine I’ll talk about later. But this is about a utility program. A way to print out BASIC code in hex. And this article is about what I did and why.
Finding inspiration again from my programming groups, the idea of an infinitely scrolling screen of text came up. There were a couple of different solutions posted, some quite ingenious. I had done something similar in the past, but this time I used a bit of machine code magic to create a more flexible solution. The result is Print Scroll.