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Play BAS Invaders - a new type-in for the Amstrad CPC

27 October 2023

I've written a new Amstrad CPC type-in for a one-off collectors' magazine called Amstrad Addict. The program is a simple version of Space Invaders called BAS Invaders, which was written 100% in Amstrad BASIC.

I remember trying to do a Space Invaders type game when I was just starting to learn Amstrad BASIC in 1985. It took so long to draw the characters on the screen that it was impossible to get anything resembling a game working.

For this type-in, I revisited the challenge and used colour swapping so that I don't need to redraw the aliens on the screen. They're all there, in every position, all the time, but most of them are drawn using an invisible ink. You can change the ink colour of something on the screen instantly, so fast animation becomes possible. It's a bit like a version of those early LCD and LED games where all the character positions are fixed on the display and light up in turn.

You can play the game in your browser, or download it to try in your emulator (where it runs a bit faster).

It was an interesting challenge to write something that makes sense as a type-in in 2023, when we can download any software we want easily. I hope that the listing and its explanation in the magazine make for an interesting read, whether or not you type the game in or run it.

Several of my other Amstrad games run in your browser too:

You can order Amstrad Addict here.

I also contribute to Amtix CPC magazine, a regular publication. If you're curious about what it's like, you can view a flipbook of issue #7 of Amtix CPC. (I don't have anything in that issue). Order back issues and subscribe here. Also available is the Amtix CPC Annual, a hardback A5 publication.

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