Watch Fishtank from Amstrad Computer User in your browser

Fishtank was a type-in listing I wrote that was published in Amstrad Computer User (ACU) December 1991. Watch the program below, and see the original listing as it appeared in the magazine.

About the Fishtank type-in from ACU

This one is really silly, for at least two reasons.

First, it's a fishtank simulator, so you just watch a fish swimming around the screen. At the time videos of fishtanks and coal fires were being sold for people to play on their TVs. I wasn't thinking of that when I came up with the idea for this. I was watching the fish in the garden pond while drinking a cup of tea. Nevertheless, perhaps that video fishtank idea had crept into my mind somewhere along the line.

The second reason this one's mad is that the listing is really rather long for the end result. Most of the listing is the sprite data, primarily the giant fish. I'm sorry if anyone typed this in and was disappointed. The magazine didn't publish any screenshots, so you had to type it in to see it.

If I was writing it today, I'd do it differently. I'd replace some some sprites with user-defined graphics (UDGs) for the sand and bricks, which would make the listing shorter. I'd probably try to draw the fish on screen using BASIC instructions, and then include a machine code routine to convert it to a sprite and display it. The listing might not be much shorter, but it would be more interesting to type in. It would be more educational, and there would be the possibility of adding in randomness to make the fish look a bit different each time.

I think I'd also make the movement smoother. This program is using a variant of my Easi-Sprite Driver code, which positions sprites using text coordinates. I later came up with a more fine-grained sprite positioning system (ESD Advanced) that would make this look much better. The sprites were created using my Amstrad CPC Sprite Definer, which appeared on an Amstrad Action (AA) covertape.

For this version of the Fishtank program, I've added a title screen that is shown while the data is poked into memory.

Download my disc of Amstrad games and utilities to use in your favourite emulator here.

The Fishtank listing from ACU

Load another game into the Amstrad CPC 6128 emulator

• Play The Further Adventures of Fred
• Play BAS Invaders (an Amstrad Addict type-in)
• Play Alien Intervention (an Amstrad Action type-in)
• Play Gribbet (an Amstrad Action type-in)
• Play Wallbuster (an Amstrad Computer User type-in)
• Watch Fishtank (an Amstrad Computer User type-in)
• Play Misfit (from my book The Basic Idea)
• Play Paclone (an Amstrad Computer User type-in)
• Play Chords Tutor (an Amstrad Computer User type-in)
• Play 3D Mapper (an Amstrad Computer User type-in)
• Use the User Defined Graphics generator
• Reset the machine and program something yourself
• How to embed the Amstrad CPC 464 / CPC 6128 emulator in your website

You can download my Amstrad CPC games and utilities disc to use these programs in your favourite emulator.

Where next?

• Sean's Amstrad CPC homepage, including Amstrad type-ins and my Amstrad BASIC programming tutorial.
• Download my disc of Amstrad games and utilities
• Read my books to learn to program in Python or Scratch