ZX81 Computer


Showcasing monthly programs, a retro look at my my first computer., Page 2
Can You Get the High Score in the Worst ZX81 Dice Game

Okay, although not the worst ever, Dice Game is pretty dull. With only two dice, no strategy, and no replay value, you might think this an odd program of the month. But for the young teenager that wrote it, it was pretty cool in 1983. Let’s dig in and see why.

Posted May 28, 2017 by Steven 7 min read

Bringing an Old ZX81 Sketch to Life with BASIC Is Absolutely Crazy

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.

Posted Apr 30, 2017 by Steven 6 min read

Bet and Win in Stud, a Simple ZX81 Poker Game

For March’s program of the month, I offer up Stud. Written in 1984, it was my first computer card game. Calling it a card game is disingenuous as Stud is a simple high/low betting game. There are no rules or even a deck of cards. Yet simple can be fun in this random poker game.

Posted Mar 24, 2017 by Steven 3 min read

Pictures Are Pretty, How to Make a ZX81 Draw

Sometimes one function can do a lot. For February’s program, picture uses a line drawing routine to draw a pretty picture. Okay, pretty is in the eye of the beholder. But, nonetheless, it is a picture. The fun, though, is in watching it draw.

Posted Feb 25, 2017 by Steven 4 min read

Can you hack the computer and save the world?

“Agent 51, your goal is within reach, but there is a problem.” “Understand,” you reply. Professional as always, you only allow a hint of annoyance in your voice. “Explain.” “Well, the plans are in the room in front of you, but the floor is a trap. You need to deactivate it using the terminal to your right.” You look down at the screen, a singular “READY” stares back at you. “Sounds easy enough,” you reply. “It isn’t. The interface is protected and, sadly, our operative died before he could tell us the code.” “So what do I do?” “You’re going to have to hack it. Our operative left a back door into the system, if you can find it. You can do it, Agent 51.” You nod at the voice in your ear. You can do this. Play begins with imagination. Computers are great for role playing and Code IV was one of my programs that helped enable a story. As a kid, I often augmented my play using my ZX81. Although the narrative above isn’t exact, it embodies what I was thinking when I wrote this month’s ZX81 program. Fun, adventurous, and a unfair, can you crack the code and disable the floor?

Posted Jan 22, 2017 by Steven 5 min read

Can you guess the right code to win?

I used to play Mastermind when I was a kid, a simple code breaking game. One player would set up a sequence of colored pegs and the other would have to guess it in a set number of turns. My version, called ZX Master Mind, has the computer creating the code. Can you guess the three numbers in sequence before your ten turns run out?

Posted Dec 22, 2016 by Steven 4 min read

Can You Avoid Death in the ZX81 Game Stick Shift?

Dodging games were the rage back in the early ’80s. Wanting to add my own take on the genre, I created Stick Shift, November’s program of the month. The goal is simple. Dodge other cars, oil spills and spikes while not crashing into the wall. Mess up? Well, it’s game over for you. Don’t fret though, it isn't that hard—yet.

Posted Nov 24, 2016 by Steven 3 min read

Bugers Will Kill You in October's ZX81 Program of the Month

While working to improve the way I display my ZX81 programs, I ran across one that didn’t have a picture. Finding that odd, I did some research and found that I’d written a page for it back in 1999. To my surprise, I’d never uploaded it. To rectify that oversight, I made Bugers this month’s program.

Posted Oct 25, 2016 by Steven 3 min read

Trail Blazer is my ZX81 Tribute to Tron’s Light Cycles

One of the coolest movies when I was a young teenager was Disney’s Tron. What geeky kid didn’t want to watch a movie about computers and video games? Sprinkle in some computer animation and how could I not fall in love. Needless to say, Tron was the inspiration for more than a few of my programs. Trail Blazer, September’s program of the month, is one of them. An homage to the light cycle segment, the goal is to crash your opponent first. But beware. All walls are deadly, including your own.

Posted Sep 18, 2016 by Steven 6 min read

Electon is August’s ZX81 Program

I painted more borders on the ZX81 than just about any other shape. An easy way to confine movement, it shouldn’t come as a surprise that Electon starts by building a box. And before you ask, this month’s ZX81 program isn’t another version of snake. Instead, you use the Z, X, N, and M keys to move in an attempt to capture the Electon. Sounds easy? Better give it a try and see.

Posted Aug 22, 2016 by Steven 7 min read

3D Image is July’s ZX81 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.

Posted Jul 20, 2016 by Steven 1 min read

Vargen Crown is June’s ZX81 Program

“Jealous of Vargen’s accomplishments, a rival kingdom has attacked and kidnapped your king. As head Knight, you mount a quest to return the King, hidden somewhere in the forest by his captors. But hurry! The King’s ransom has a time limit.

Posted Jun 27, 2016 by Steven 2 min read

Up Is Down in Faller, May’s ZX81 Program

Walls and creatures always make for a nice game and Faller, our program of the month, has both. It takes a bit of imagination, but watch the icky spider climb up the wall towards you. Their goal, of course, is to knock you off and claim the wall for themselves.

Posted May 21, 2016 by Steven 1 min read

Laser Blast is April’s ZX81 Program of the Month

April is close to wrapping up and I was able to find time this weekend to type in another ZX81 game. Laser Blast, this month’s program, has you saving the world. Kind of cliché I know, but hey this was 1984. George Orwell’s novel didn’t come true, but at least we could blast alien’s with lasers.

Posted Apr 27, 2016 by Steven 1 min read

Computact is March’s ZX81 Program

Ah, spring time. As winter melts away, the weather goes haywire and it’s time to enjoy the bouts of sunshine, rain and the occasional thunderstorm of hail. Perhaps it’s fitting that in the middle of this meteorological mayhem that Computact came back to life.

Posted Mar 22, 2016 by Steven 1 min read

February’s ZX81 Program: Telaport

Digging through my listings, I struggled deciding what to offer for February. The first one I found was an adventure text game. Too close to last month's program, I decided against it for now.

Posted Feb 27, 2016 by Steven 1 min read

January’s Program: Star Probe

Wow, 2016 and I'm still digging programs out of my stack of print outs. Kicking off the new year, I'm grabbing a story based program. I wrote Star Probe, our program of the month, in the style of a Chose Your Own Adventure book—and yes, I actually owned most of them.

Posted Jan 26, 2016 by Steven 1 min read

December’s Program: Monkey Maze

Time to close out the year with another classic remaking. Back in 1983, I decided to try my hand at recreating Nintendo’s fan favorite: Donkey Kong. My version, cryptically called Monkey Maze, is December’s Program of the Month.

Posted Dec 29, 2015 by SafePit 1 min read

November’s Program: Dragon’s Lair

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.

Posted Nov 29, 2015 by SafePit 1 min read

October's Program: The Haunting

It is Halloween and October’s Program of the Month is right on time. When I pulled listing for The Haunting from my stack I knew it would be perfect. Although short, I knew I’d be challenged as this program of the month requires something I hadn’t needed before.

Posted Oct 31, 2015 by SafePit 1 min read

September's Program: Input Two

To my surprise, I was thumbing through my old printouts and discover that I actually wrote an Input Two program. I covered Input One as March’s Program of the Month. For September, however, it is Input Two’s opportunity to shine.

Posted Sep 20, 2015 by SafePit 1 min read

August's Program: Canyon Raider

While reading through my old programming notebook last month, I wondered about using them on my website. From my earliest programming days, the notebook has a number of programs that never made it to my stack of printouts. Canyon Raider, August’s program of the month, is one of those programs.

Posted Aug 22, 2015 by SafePit 1 min read

July's Program: A Story

Whoops! I completely missed posting this. Either I meant to and didn’t hit submit or just plain forgot. Either way, July’s program is indicative of the BASIC programs you’d find in early programming manuals. Most books start out with pretty basic commands such as PRINT and INPUT.

Posted Aug 17, 2015 by SafePit 1 min read

June's Program: Fly

Fly is a simple program that end the end is both baffling and intriguing. Looking at first like a simple shooter, it acts very differently then one and, if you don’t know the rules, will make you crazy. Once you do know how to play, though, Fly becomes simple and repetitive.

Posted Jun 28, 2015 by Steven 1 min read

May's Program: WIZERDRY

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.

Posted May 31, 2015 by SafePit 1 min read