ANDESITE

A ZX Spectrum Next emulator that targets the Next itself, not the older Spectrums it can imitate. The CPU, the video and the sound all run from one shared clock, so a game that changes CPU speed mid-frame stays in step with the display.

Layer 2 in all three modes, the ULA with every Timex mode and ULANext, LoRes, the tilemap and the 128 hardware sprites are combined using the layer order, per-entry priorities and both blend modes. The Copper runs in the same pass, so each register write takes effect on the exact dot it was meant for.

Games load as .nex files, snapshots, zip archives or complete SD card images; anything that isn't already a card gets one built for it on the fly. esxDOS itself is not included; instead, the file and directory calls programs make through RST $08 are emulated on top of the card's FAT volume, so games can read and write their own files, including high scores and saved progress. Sound comes from the beeper, three AY-3-8912s through Turbo Sound Next, and the four 8-bit DACs, mixed in stereo through a band-limited buffer. Sprites, the tilemap, the Copper, the ZXN DMA, the Z80 CTC, the Kempston mouse, the DS1307 clock and save states each have their own test suite.

Available on Windows, Linux, macOS, Android, iOS, and WebAssembly. Andesite is written in plain, portable C11 with no unusual dependencies, so porting it to game consoles is straightforward. Contact us if you are interested.

Retro City Skyline

Andesite in Action

Unmodified commercial games running on Andesite.

Black & White running on Andesite
Black & White © Pat Morita Team
Bonsai Next running on Andesite
Bonsai Next © JuanGM
Delta's Shadow running on Andesite
Delta's Shadow © Sinc LAIR
The Lost Temples running on Andesite
The Lost Temples © Pat Morita Team

Andesite Options

Third-Party Software