ZX81 Computer


Showcasing monthly programs, a retro look at my my first computer., Page 7

February’s Program: Enlarger

February’s Program: Enlarger

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.



December’s Program: Thyime

December’s Program: Thyime

December is upon us and Thyime is the last program of the month for 2012. My how quick the year has passed. Thyime’s elements include moving, shooting, a break through wall, and a moving enemy. It does all this while remaining fast. Thyime provides a decent game to close out the year.


Bonkers! Redux

Bonkers! Redux

I couldn’t help it. I updated Bonkers using MCODER II to convert the BASIC code to Machine Language. This improved the speed of the game making improving its playability. If you haven’t played the 1985 version, play it first so you can appreciate the difference. If you have, now give the 2012 version a try. Better?



October’s Program: PAC-MAN

October’s Program: PAC-MAN

October’s program, PAC-MAN, may leave you a bit confused. Inspired by that iconic arcade game, this version has no graphics. It does have dots, cherries and ghosts. It doesn’t, however, have any pictures of those elements. Give it a try and you’ll see what I mean.


September’s Program: Runner

September’s Program: Runner

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.


August’s Program: PAC-MAN Video

August’s Program: PAC-MAN Video

Wow, August flew by way faster than I expected! Here we are at the end and I finally got around to uploading the monthly program. This month’s program, PAC-MAN Video, is a bit different. Although I call it a game, it doesn’t really play like one. It is totally random with a slight nod to you. Skill isn't required, just give it a try.


July’s Program: Can Punch

July’s Program: Can Punch

I’m back to the basics for July’s program. Can Punch is a simply graphic game that will probably infuriate you more than entertain. Don’t believe me? Go try it and decide for yourself. The goal is punch the can thrown at you. Use Z to raise your fist high and . to lower it. A deceptively simple game mechanic that I dare you to master. I double dog dare you!


June’s Program: Pole Dodge 2

June’s Program: Pole Dodge 2

Yes, I know I’m late. June is almost over and I’m sure my adoring fan is up in arms. I do have one fan, right? In any case, I’m breaking tradition for June’s Program of the Month and posting a more modern program. Pole Dodge 2 is my revamped version of April’s program. Before I dig into the details, go play it. It’s real easy, just use the “Z” and “.” to bank left or right. No really, go play it. I think you’ll find it much more enjoyable this go round.


May’s Program: Jet Flyer

May’s Program: Jet Flyer

Jet Flyer is May's Program of the Month. Although a bit late, I believe it is a bit better than last month's and worth a quick try. The goal is to keep your jet on course by using the “Z” and “.” keys to bank right or left. It isn’t an overly hard game. You just need to keep the course indicator close to zero. I won’t say how close to avoid spoiling the fun.


April’s Program: Pole Dodge

April’s Program: Pole Dodge

Pole Dodge is April’s Program of the Month and it is an odd one. Partially odd because I typed it in back in February, and partly because the program just doesn’t play well. I know that doesn’t lend well for one to give it a try, but try it you should. Why? Because the premise isn’t bad. It is the execution that leaves a bit to be desired. Of course, I blame the slow hardware.


March’s Program: T.W.M.

March’s Program: T.W.M.

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.


E.T. Redux

E.T. MC, Finding a Flower, 2012 by Steven Reid

E.T. may not have been my best game ever, but it was an interesting exercise in 1985. Loosely, and I really mean loosely, based on the Atari 2600 game, E.T. follows the exploits of the title character as he tries to find his way home. Originally written in ZX81 BASIC, I revisited E.T. to better understand how to use MCODER II. I was ultimately successful in compiling it and getting it to run. If you are adventurous, you can compare it to original version, bugs and all. Instructions for E.T. are available off my old ZX81 website.


Playing Around With Wordle: Elevating ZX81 Content Through Word Clouds

Playing Around With Wordle: Elevating ZX81 Content Through Word Clouds

It isn’t all programming around here! Some days it is fun to just play around. I was adding an image to my other site which led to me reviewing some of my old Flickr images. This got me playing around with Wordle again to see what Tag Clouds I could build form the ZX81 articles.



February’s Program: Light Walls

February’s Program: Light Walls

February is upon us and that means another program of the month. This month it is another one from 1983: Light Walls. In case you hadn’t guessed, it has its roots in Tron. The game requires you to steer right (“.”) or left (“z”) to avoid hitting the light walls. I wrote this program while a friend was over and we took turns trying beat others high scores. Who says you need color and 3D graphics to have a good time! Not convinced. Give it a try yourself and see how good your reactions are.


ZX81 Emulator on Android

ZX81 Emulator on Android

As more and more people turn to mobile and tablet devices for their entertainment and consumption needs, it is becoming harder to share my ZX81 preservation project. I remember how excited I was when I found a Java based emulator that would run my ZX81 programs on the web. Although Java and I haven’t always gotten along, I was happy to be able to show off my programs on the go with nothing more than a browser available. To my surprise, however, Java isn’t even part of the conversation when talking about those on-the-go OS’s like iOS and Android. All that effort isn’t of much use when a large portion of your audience can’t enjoy it. Fortunately, and much to my surprise, I ran across Zed Ex (Beta) in the Android Market. You can also find it on AppBrain.com.


January’s Program: Road Hog

January’s Program: Road Hog

Welcome to the new year! Starting off the second season of monthly programs is January's program Road Hog. Road Hog is a driving game similar to my later Flywheel game. I hesitate to call it a racing game as there is no acceleration. You just move the car left or right using the Z or . keys. The game is pretty easy due to the slow speed of the animation. Go give it a spin.


A New Year of ZX81 Programs

ZX81 Computer

Well, the celebration of thirty years since the introduction of the ZX81 is now over. For the last year I've been bringing you an original ZX81 program each month as a tribute to my first computer. It was a lot of fun typing in those old programs or fixing tape recordings I made back in the eighties. I even rewrote one which brought me back to those old programming days. For those that found your way here, I hope you enjoyed my ramblings about the programs. Perhaps you've learned something or I just invoked a kinship from a fellow programmer.


December’s Program: Creature

December’s Program: Creature

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.


New RSS Feed

ZX81 Computer

As of today, you can use RSS to subscribe for your monthly dose of ZX81 goodness. I originally hadn’t planned to offer an RSS feed for my ZX81 site. The original goal was to cross-post articles to my main site and rely on its feed for subscribers. Sadly I tend to forget to cross-post.



October’s Program: 1985

October’s Program: 1985

October’s program is one of my later games from 1985 which is aptly named 1985. It has decidedly simple game mechanics. Set in an alternative reality, the Earth is gone in this version of 1985. Humans are colonizing Earth II, but you need to clear the mountains for agriculture needs. Yes, your job is to hit any key to clear the land. Things couldn’t be easier, right?


September’s Program: Odyssey

September’s Program: Odyssey

This month I present another simple game, Odyssey. It doesn't include instructions, so here is a quick synopsis. An evil computer has trapped you in a space ship. To escape, you have to remove the memory boards in order to shut down the computer. Sounds familiar? Obviously this program was inspired by 2001: A Space Odyssey. To play, use “Z” to move left and “.” to move right. Hit the “M” key to remove a memory card. Try to remove all of them in time to beat the computer.