Arcade Coin-Op Simulator ( A.C.O.S. )

Arcade Coin-Op Simulator 

Volume 1 - Star Force – ZX Spectrum Next Edition

A faithful port of Tehkan’s legendary 1984 vertical shooter, meticulously rebuilt for the ZX Spectrum Next.

Travel back to the golden era of arcades with this almost perfect port of Star Force, rebuilt in pure Z80 assembly and using the original code to run seamlessly on Next hardware. Every effort has been made to preserve and recreate the experience of the original Tehkan (now Koei Tecmo) arcade game, while embracing the unique capabilities of the Next.

Features

• Full recreation of the original arcade gameplay, smooth 50Hz / 60Hz scrolling, and identical enemy behaviour.
• Authentic multi-layer rendering using Sprites, Layer2 and Tilemap to simulate the arcade hardware’s multi-plane visuals.
• Faithful sound emulation re-engineered for the Next’s CTC, triple AY-3-8912 chips and DAC, replicating the tone of the original 10 channel sound hardware.
• Caravan Mode – a time-based high-score challenge inspired by the Nintendo Switch Arcade Archives version of the game.
• Developed entirely in Z80 assembly, tested using the CSpect emulator & Real Next Hardware with near-native performance.
• Added settings screen allowing customisation of the game configuration, controls and display mode.

Download and experience Star Force as it was meant to be — smooth, fast, and fiercely addictive on real Next hardware.

Join the ZX Next Star Force conversation on Discord here.

(This is an unofficial fan project based on Tehkan’s Star Force arcade game.)

Development Journey

This project was born from a lifelong fascination with classic shoot-’em-ups and an obsession with achieving smooth sprite animation.

After teaching myself Z80 assembly in the 1980s, I set out to do what the original ZX Spectrum couldn’t — bring the arcade home without compromise. Over thirty years later, the ZX Spectrum Next provided the features to make my dream a reality.

Credits

Development, code, adaptation and tooling by me!

Special thanks to the ZX Spectrum Next community, including Peter Ped Helcmanovsky, David Saphier, Jim Bagley, Richard Faulkner, Michael "Flash" Ware, Ronnie Simpson and many others.

Important Note on Original ROMs

To run this port, you must supply your own or legally obtained original Star Force arcade ROM files.  A dedicated tool is included in the download that will combine your legally obtained ROM with the ported game code automatically.

I do not in any way condone piracy.