After finishing the basic version of the cat animation, I wanted to improve the frame speed. This meant converting from BASIC to machine code. My first thought was to do the conversion with MCODER II. I dropped that idea, deciding to focus on a custom z80 Assembly version. Ergo, cat written in assembly or Fast Cat is, well, a faster version and a bit more.
A recent post in a Facebook BASIC group of a cat animation. A couple of other members converted it to their BASIC code of choice. Mine being the ZX81, I promptly worked on a version for it. I created a mostly full screen version, which tends to show how slow the ZX81 really was. In any case, it was quite a fun little exercise.
I was hoping to have finished Gem Quest by now, but May didn’t afford much time. With Summer arriving and the pandemic seeming to be winding down, at least in Boise, my attention is elsewhere. With a short list of ideas, I decided to play off last month's theme. Picture in Motion isn’t new, but it is more interesting to watch.
The eighties were a turbulent time. Political turmoil grew out of the Cold War, which wasn’t loss on this teenage programmer. The vocal leaders of the US and the USSR bubbled up often in the pop culture of the era and the esclation of war. It shouldn’t be surprising that I’d create an animation depicting that escalation.
Foreign to many developers today, I have a notepad and binder full of ideas from my ZX81 days. The notepad contains early program snippets. In contrast, I have sketches and designs crammed into a binder. Flipping through it, I landed on a Star Wars sketch that became the basis for this month’s program.
Not everything I wrote on the ZX81 was a game, although I did write a lot of those. In fact, some of my first computer programs did nothing more than print pictures. 3D Image, a badly named program, is one of my experiments in animation on the ZX81. Depicting a sun at the end of its life, it’s a uses simple math to generate an image.
One of my favorite video games as a kid was a rather unlikely one. It wasn’t the coolest graphics or excellent control. It was about story and animation. It was, of course, Dragon’s Lair. The odd laser disc game by famed animator Don Bluth. Not surprisingly, I tried to recreate a bit of the game's feel on my ZX81. My attempt is, of course, November’s Program of the Month.
Okay, you may be wondering why there is a picture of an Apple II on a ZX81 site? I’ll start by saying that it’s been a pretty busy May with lots of travel for both business and vacation. The picture is from the Smithsonian and it actually does relate to May’s program of the month, Wizerdry. Yep, I spelled that wrong. I'll chalk it up to being young. Can you guess the tie yet?
Sorry, still no Joust. It’s not where I want it and I’ve spent July working on my novel instead. That isn't to say that I’m going to leave July without a program of the month. Instead I’ve pulled from my original site to bring you one of my favorite programs, Block £ Spear. In this game you'll find yourself at the wrong end of a knight’s spear. Fortunately, you have a shield and can easily deflect the spear by using the Z and . keys to raise or lower your shield. Sounds easy? You might be surprised.
I actually started working on May’s program of the month, Joust, about three weeks ago. My goal was to update the program to a faster and more fluid MCODER version. Sadly, things haven’t gone so well. Pressed for time, I will leave you instead with my original take on this popular arcade from the 80s.
April has been a crazy month. I decided to try something new, pushed along by an unexpected event. I’m writing a book. I joined NaNoWriMo just after last November's event so I didn't expect to do anything until later this year. The surprise was there CampNaNoWriMo event in April. Not to waste the opportunity, I’ve been busy crafting my Sci Fi novel and am now in the final stretch to my 50,000 words goal. Add on top of that a business trip and a family trip and you'll quickly see that my ZX81 hobby gets pushed by the wayside.
For March's program of the month, I drew inspiration from one of my older demo’s, The Ball. Like many young kids from the early eighties using BASIC, I took a stab at animating a bouncing ball. It is a a relatively easy program to write depending on how complex you want to make the math. In my case, it is very simple math, no physics involved here.
The old saying “time flies when you’re having fun” is so true of late. This year started with a bang and I feel like I’ve been running ever since. It isn’t that I haven’t wanted to work on my old ZX81 programs, but they often take a back burner to other past times. That said, I did find some time to sit down this weekend to type in another program. For February I present you with ENLARGER.
September’s program, Runner, is nostalgic for me. When I wrote this program I had moved on to my C64. My ZX81 was starting to gather dust as I was busy learning the ins and outs of my new computer. For some reason, something tugged at me to fix my ZX81 keyboard and get it running again. After transplanting the ZX81 brains into a TS1000 case, it surprisingly powered on. I wrote Runner as a test that still worked. It did. That was the last time I was able to use the computer that had been my pride and joy for the previous three years.
T.W.M. is March’s program of the month. It is a simple animation that tries to mimic a computer’s destruction of its defined target. February was actually pretty prolific for me as I transcribed this and another program, as well as updated a number of older programs using MCODER. Fortunately, that means I have a few more programs available than I normally do. Of course, one is more than I normally have ready so I’m not sure that means much. Anyway, go give it a try and enjoy the animation in all its simplicity.
I can’t believe December is here and the year is almost over. To celebrate the last program of the month, I present Creature, an animation program. Unlike many of the smaller programs submitted throughout the year, this one is the largest weighing in at 14KB. Although Creature isn’t as exciting next to more modern computer animations, I still find it interesting to see what could be done with this little machine 26 years ago. Give it a watch, enjoy the nostalgia, and try not to laugh too much.
I was searching through my stack of programs and decided to choose a short and sweet program for June. Beo One is definitely short, clocking at just 33 lines of code. Well 35 if you include the two new save and run lines I added. This is a simple talking head graphic program, which is the sweet part.
I’ve been a bit busy this month so I choose a relatively short program in order to not miss my self imposed deadline. To that end, I present to you April’s belated graphic program: Sphere. This program will easily run on a 2K ZX81. With some trimming, if you are so inclined, it will probably run in the original 1K of RAM as well. Although I doubt too many people with a ZX81 have less than 16K of RAM. Take a look at the listing to get a feel for how small this program really is.
I finally got around to trying my hand again at animating some of my virtual LEGO creations. I decided to go simple and animate the vanes and a simple camera pan for the promotional Windmill circa 1976. And, to really get my geek on, I uploaded it to YouTube.
A few years back, I started to convert some of my old ZX81 programs so they could be use in various ZX81 emulators. That project was mostly my way of trying to preserve some printouts from my now faded programs. I was curious if I there was a way to emulate those programs in a web site. Surprisingly, the answer is yes!