Homebrew tools for retro development

TwistedRaven is one person building the retro-development tools I always wished I had — an assembler, a language and an emulator, made for the fun of it.

Bizmuth

v1.0.0-beta1

Run & debug

A ZX Spectrum Next emulator with a source-level debugger, breakpoints and scripting.

The Bizmuth emulator →

FantASM

v1.9.0

Assemble

A cross-platform Z80 assembler — the complete Z80 and Z80N instruction set, macros, structs and Rhai scripting — with first-class ZX Spectrum Next support.

The FantASM assembler →

Zinc

In development

Write

A modern, Rust-flavoured language that compiles straight to Z80 — high-level ergonomics, no runtime overhead.

The Zinc language →

Other tools

0x1DE

Extension

The VS Code / VSCodium extension — FantASM language support and Bizmuth source-level debugging in your editor.

Get 0x1DE →

Rookery

macOS

A macOS menu-bar host for a Gitea act_runner — keeps a self-hosted CI runner connected.

About Rookery →

Latest news

All news →

Aug 23, 2026

Bizmuth beta

Bizmuth 1.0.0-beta1 is available

Bizmuth 1.0.0-beta1 is available to download — the first beta of the 1.0 line, and the release where Bizmuth starts running on hg80, our own Z80 and Z80N CPU co…

Aug 22, 2026

FantASM

FantASM 1.9.0 is available

FantASM 1.9.0 is available to download. One project file can now build several images, the language server finally knows what machine you’re targeting, and ther…

Aug 19, 2026

FantASM

FantASM 1.8.0 is available

FantASM 1.8.0 is available to download. It’s a big one: modules grow up, the !test simulator changes CPU, and there are four breaking changes — read those first…

Early days yet — three tools so far, and more whenever the itch strikes.