Home > Books > Amstrad CPC > Play Fishtank (ACU type-in)

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. I used this technique for my 2024 listing Anaglyph Aliens for Amtix CPC magazine. In Fishtank, there would be the possibility of adding in randomness to make the fish look a bit different each time.

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

Scan of a magazine page showing the code listing for this program Scan of a magazine page showing the code listing for this program

Load another game into the Amstrad CPC 6128 emulator

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

Where next?


© Sean McManus. All rights reserved.

Visit www.sean.co.uk for free chapters from Sean's coding books (including Mission Python, Scratch Programming in Easy Steps and Coder Academy) and more!

Discover my latest books

Coding Compendium

Coding Compendium

A free 100-page ebook collecting my projects and tutorials for Raspberry Pi, micro:bit, Scratch and Python. Simply join my newsletter to download it.

Web Design in Easy Steps

Web Design IES

Web Design in Easy Steps, now in its 7th Edition, shows you how to make effective websites that work on any device.

100 Top Tips: Microsoft Excel

100 Top Tips: Microsoft Excel

Power up your Microsoft Excel skills with this powerful pocket-sized book of tips that will save you time and help you learn more from your spreadsheets.

Scratch Programming in Easy Steps

Scratch Programming IES

This book, now fully updated for Scratch 3, will take you from the basics of the Scratch language into the depths of its more advanced features. A great way to start programming.

Mission Python book

Mission Python

Code a space adventure game in this Python programming book published by No Starch Press.

Cool Scratch Projects in Easy Steps book

Cool Scratch Projects in Easy Steps

Discover how to make 3D games, create mazes, build a drum machine, make a game with cartoon animals and more!

Walking astronaut from Mission Python book Top | Search | Help | Privacy | Access Keys | Contact me
Home | Newsletter | Blog | Copywriting Services | Books | Free book chapters | Articles | Music | Photos | Games | Shop | About