New 3D Amstrad game: Anaglyph Aliens

19 June 2024

I've written a new listing for the final issue of Amtix CPC magazine, which has just been published. It's a game called Anaglyph Aliens that uses 3D red/blue glasses to make aliens fly out of the screen at you.

I've long held an interest in 3D effects. One of the first articles to go live on this website more than 25 years ago was about stereograms, and my book Cool Scratch Projects in Easy Steps showed you how to make 3D games using Scratch (and included a pair of the glasses).

I was curious about whether it would be possible to create a 3D game for the Amstrad. It all came down to how well the machine's built-in colours matched the lens colours in 3D glasses. While there was some ghosting as a result of colour leakage, the 3D effect worked. I wanted to make sure the game design used the depth as a gameplay element, and not just background scenery, so the aliens fly towards you.

I also wanted the program to make sense as a listing, intended to be read and typed in. In the 90s, listings often had lots of sprite data, which was boring to type in. This wasn't really questioned at the time because there was no other way to get the software, other than buying it on tape which was unviable for most short programs. Now that we can easily download software, there's little appeal in reading or typing in a listing that is unintelligible.

To that end, this listing draws the aliens in BASIC, and then uses a tiny machine code routine to convert them into sprites. I really wish I'd had this idea in the 90s. It would have made Fishtank a more interesting and shorter listing, for a start, even without changing the experience while it was running. Anaglyph Aliens also uses the small machine code routine as music data, so that it's possible to have a (strange) jingle before each game, without needing to type any music data in. (I didn't include this line in the mag version, to save space).

It surprises me when I find myself thinking of a new coding technique on the Amstrad, given I've hardly used the platform for years. It feels like my old programming knowledge from my well-spent teenage coding years is still there, but enhanced by the things I've learned since about user experience and the time I've spent programming in Python and Scratch.

Play Anaglyph Aliens in your browser now, or download the disc. If you don't have a pair of glasses to hand, you can order them cheaply on eBay, or find a pair in Cool Scratch Projects in Easy Steps.

As I said, issue 12 is sadly the final issue of Amtix CPC. For this last issue, I've also written a short history of the CPC seen through the final issues of the major magazines and a Flash Back review of Highway Encounter. Over the last few years, the magazine has published 12 issues, plus an annual, coming to a total of about 750 pages. It's been a joy to read and to write for. Thanks to the publisher Chris, editor Colin, the contributors and the readers for making it happen. If you have any gaps in your collection, back issues are available here.

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New free ebook: Coding Compendium

03 June 2024

I've published a new ebook that compiles more than 100 pages of tutorials I've written for Raspberry Pi, Scratch, Python, and the micro:bit. It's called Coding Compendium and it's free to download when you subscribe to my newsletter.

The ebook compiles the articles I've written over the last ten years for publications including The MagPi, Hello World, Raspberry Pi Geek, micro:mag, and my website. A single PDF compilation seems like a more useful resource than having them languishing in the archives, including for me when I need to refer back to a previous coding project to remember how I did something.

In compiling the ebook, I took the opportunity to update my article on using the Python turtle (a great way to move from Scratch to Python), and added a new article about getting Scratch 2 projects working with Scratch 3. Some of the older articles were created with Scratch 2 and there are many great resources available for Scratch 2 (including some of my books which haven't been updated). There are just a few small differences between the two versions of Scratch, so projects from Scratch 2 will work fine on Scratch 3, but some of the blocks are in a different place in the user interface.

I hope that the ebook also promotes the magazines where the articles were first published. While the magazines' licences allow anyone to share their contents, I try to share them in a way that respects the magazine's investment in the work. I don't share PDFs of articles until the magazine issue has long gone off sale, so that there's no risk of my site competing with the magazine. You can support The MagPi by subscribing or by donating when downloading the magazine's PDF edition, and can subscribe to Hello World for free (in print if you're an educator, and in PDF for everyone).

This is the first time I've gated content, by requiring people to sign up to my newsletter to download it. Social media has collapsed over the last year or so, as a way to reach people with new articles and books. I hope that this ebook will help me to build a list of people who are interested in the kinds of things I make and write about, so I can keep them informed with occasional emails.

See more information, including the table of contents.

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