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-rc1

Run & debug

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

The Bizmuth emulator →

FantASM

v2.2.0

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 →

Oct 4, 2026

Bizmuth

Bizmuth runs in your browser

Bizmuth now runs in your browser. Try it online: press a machine’s button and it boots.

Oct 2, 2026

FantASM

FantASM 2.2.0 is available

FantASM 2.2.0 is available to download. The linker grows up: fantasm link places sections by a link map, writes fxi version 3, and carries !test blocks from obj…

Oct 2, 2026

Bizmuth

Bizmuth 1.0.0-rc1 is available

Bizmuth 1.0.0-rc1 is available to download — the first release candidate for 1.0.0. The headline is speed: emulation is faster, and the emulator spends much les…

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