ZX81 Computer


Showcasing monthly programs, a retro look at my my first computer., Page 4
Aprilís Program: RMS

Are there any D&D folks in the audience? Come on, you know who you are. Past or present doesnít matter, just if you know what Iím talking about. Why, you ask? Because RMS, Aprilís program of the month, will use your ZX81 to build monsters. Any fledgling DM could then use these creatures in their latest campaign. Elves and humans will cringe at your originality and cruelty.

Posted Apr 29, 2015 by Steven 4 min read

Marchís Program: Input One

Input One, Marchís program of the month, is a great example of the kind of simple and brute force programming of the 1980s. This was a time when computers had little memory and their users had to use simple BASIC programming to get things done. The alternative was to buy a cassette tape of programs that took minutes to load even short programs, assuming they loaded at all. For the rest of us, we either typed them in or wrote little programs like this.

Posted Mar 29, 2015 by Steven 3 min read

Februaryís Program: Math Bash

At the one level, you can sum up most programs into three big groups: business, gaming, or educational. Most of my programs fit into one of these base categories. The standouts are generally the animation or demo programs that really have no distinct genre. Even those, however, I can†lump into one of the big three without much effort. There are times when these categories get blurred and a program can fit into two or more categories. This monthís program is one of those.

Posted Feb 22, 2015 by Steven 5 min read

Januaryís Program: Comp. Talk

Mixing things up a bit, I thought Iíd start off the new year without a game program. Instead, Januaryís program is Computer Talk, or Comp. Talk for short. Comp. Talk is one of several educational programs I wrote for reasons Iím not entirely sure of. Perhaps it was just the thing to do back in then. Many computer books, especially those that taught programming, had a mix of program genres. Whatever the reason, I wrote Comp. Talk as a way for the ZX81 computer to introduce itself and show a bit of what it could do.

Posted Jan 24, 2015 by Steven 2 min read

Decemberís Program: V Water Battle

As 2014 comes to a close, I wanted to end the year with an original program of the month. For December, that program is V Water Battle, an action game from 1984. For some reason, the title screen I created said designed instead of wrote but I did both. I was an odd duck in 1984. You use the ďZĒ and ď.Ē keys to move. Use the ďMĒ key to fire. The goal is to stop the ships from stealing the water. Miss them or get shot and its game over. Of course, they steal the water after each wave anyway to make it harder.†Given that I†havenít beat it yet, the game is more†difficult than it would seem. Let me know if you do!

Posted Dec 29, 2014 by Steven 3 min read

Novemberís Program: Maze Craze

Hope everyone in the US had a great Turkey Day (Thanksgiving) and are now enjoying the last weekend of November. Iím busy with NaNoWriMo, and a bit behind. So I give you another program from my original ZX81 site, but not yet featured here. Novemberís program is the month is Maze Craze. Itís not hard, but you might need to graph out the maze if you get stuck. There are actually two mazes. Can you beat them both?

Posted Nov 29, 2014 by Steven 2 min read

Octoberís Program: NA

Whoa, there are still almost two weeks left in the month and I have Octoberís program done and waiting for you. Yep, you heard right. This month is a short one called NA. The program is an action game that requires you to use ďNĒ and ďAĒ to try to stop a runner. The letters have significance as you use them to stop the runner. However, there is a twist, miss and the program changes the letter needed. Sounds easy right? Guess what, I still havenít beaten it. Can you?

Posted Oct 21, 2014 by Steven 2 min read

Septemberís Programs: Photon í85 and í98

Well, the month is over and life has taken over and delayed my program of the month. For the tail end of September, I offer two programs: Photon and Photon 98. Wait, what? Yep, you heard right. Iím offering two programs this month. Sort of.† Actually they are very similar. Photon is the original program from 1985, and Photon 98 is a minor remake that cleans things up a bit.

Posted Sep 30, 2014 by Steven 2 min read

Augustís Program: Cave War

Augustís program is Cave War, a later program from 1985. It starts out similar to Hit Man, basically a scrolling dodge the wall game. But there is more to it than that. Once you get to the end of the tunnel, you find yourself in a cave and need to blast away at a wall to continue on. Oh, and if you hit the same spot twice, it resets. Can you make it out of the cave alive? Use ďZĒ and ď.Ē to dodge the walls and ďXĒ to blast away the ground. Good luck!

Posted Aug 24, 2014 by Steven 4 min read

Julyís Program: Block £ Spear

Sorry, still no Joust. Itís not where I want it†and Iíve spent July working on my novel instead. That isn't to say that Iím going to leave July without a program of the month. Instead Iíve 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 knightís 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.

Posted Jul 23, 2014 by Steven 3 min read

Juneís Program: Monster Maker

Okay I havenít finished my remake of Joust yet, nor did I want to wait until the last week of the month to get an article out. Instead, I offer you Monster Maker as Juneís monthly program. Itís pretty straight forward and anti-climatic against the power of todayís programs. Once you load it, enter in five numbers and type your monsterís name. Thatís it. The program will then display a nicely formatted monster description based on your input.

Posted Jun 08, 2014 by Steven 3 min read

Mayís Program: Joust

I actually started working on Mayís 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 havenít gone so well. Pressed for time, I will leave you instead with my original take on this popular arcade from the 80s.

Posted May 28, 2014 by Steven 5 min read

Aprilís Program: Flywheel

April has been a crazy month. I decided to try something new, pushed along by an unexpected event. Iím 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 their CampNaNoWriMo event in April. Not to waste the opportunity, Iíve 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.

Posted Apr 27, 2014 by Steven 3 min read

Marchís Program: The Ball Redux

For March's program of the month, I drew inspiration from one of my older demoís, 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.

Posted Mar 29, 2014 by Steven 4 min read

Februaryís Program: Time

For February, I give you Time, a simple landing game with a twist. Using the Z and . keys, you maneuver your craft to each successive landing pad. If you miss the landing, keep trying but be careful. Run out of time and itís game over! How high of a score can you amass? A fair warning, Time isnít always fair.

Posted Feb 16, 2014 by Steven 4 min read

Januaryís Program: Fireball

Januaryís program of the month, Fireball, marks a first for me. Although Iíve used a few different methods to type in my programs, Iíve always gone back to a Windows so I could use EightyOne to generate the program files and images. However, for my birthday, my wife took me to the Apple store and I upgraded my old laptop to a shiny new MacBook Pro.

Posted Jan 05, 2014 by Steven 5 min read

Decemberís Program: Dollar Sign

Winter has set in and it is time to close out the year with a simple game. Dollar Sign, Decemberís program of the month, is that game.

Posted Dec 30, 2013 by Steven 4 min read

Novemberís Program: SNUNCH ML

For November, Iím looking both forwards and backwards. Although I wrote SNUNCH in 1983, I added a corrected version to my first ZX81 web page in the í90s. SNUNCH was my early attempt at writing a PAC-MAN like game. Note that I said like, not clone. My goal was to be inspired, not to copy. Sadly, it isnít very good, even after I fixed some of its logic flaws. Despite its flaws, I still believed it had potential and I set about updating it using MCODER II. It is this improved SNUNCH ML version that I offer as Novemberís program of the month.

Posted Nov 30, 2013 by Steven 7 min read

Octoberís Program: Space Dock

Since itís been a few months since Iíve presented an animation program, I hereby offer Octoberís program of the month Space Dock. Written when the space shuttle program was in full swing, Space Dock depicts a shuttle launch for its scheduled docking to repair a satellite.

Posted Oct 19, 2013 by Steven 4 min read

Doing Some Fall Cleaning

I took a break from educating myself on z80 machine code, more on that later, to fix a few things that have bugged me about the site. They are minor and probably will go completely unnoticed by most, but I wanted to make a quick note for future reference. Hey thatís what blogs are for, right?

Posted Oct 01, 2013 by Steven 3 min read

Septemberís Program: S.M.P.

Octoberís program of the month is S.M.P. or Sinclair Memo Pad. A simple scrolling editor that allows you to take a couple of quick notes that last as long they are on-screen.

Posted Sep 21, 2013 by Steven 3 min read

ZX81 Nixie Clock

While searching for some code examples I ran across this inventive hardware expansion. Michel created a ZX81 Nixie Clock and has been kind enough to share his creation with the world through Facebook.

Posted Aug 29, 2013 by Steven 2 min read

Augustís Program: Parachute

Whoa, itís August already? Time for another program of the month. Coming your way is Parachute, a deceptively simple reflex game that uses recognizable graphics to give you an enjoyable causal gaming diversion. Iíve been staring at this program for months now as it was sitting on the top of the stack. The airplane and parachute graphics stand out prominently in the listing, making it hard not to notice. As much as I tried to ignore it, Parachute was calling me to type it in. I finally caved and obliged.

Posted Aug 08, 2013 by Steven 3 min read

No Spaces for You

I wasnít sure in my last post how to remove the extra space from the program listings. Well, I figured it out.

Posted Aug 08, 2013 by Steven 1 min read

Updated Program Listing

Awhile back I went searching for a decent ZX81 font and ran across ZX81 VDU. I played around adding it to my siteís footer, but I really wanted to do more with it. Itís pretty good and, unlike some other fonts I found, it has all the ZX81 graphic characters. You do have to carefully choose the font size, but that is minor issue. Overall a great font that is easy to use.

Posted Aug 04, 2013 by Steven 2 min read