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ZX Spectrum

ZX Spectrum icon ZX Spectrum logo

Overview

The Sinclair ZX Spectrum debuted in 1982 with an affordable, keyboard-first design and distinctive attribute-based colors. REG-Linux lists ZX Spectrum entries under zxspectrum, with hand-picked ROMs powering the libretro: fuse core and an optional low-latency Clock Signal plugin.

Technical specifications

  • CPU: Zilog Z80A clocked at 3.5 MHz.
  • Memory: 16 KB RAM in the 16K model, 48 KB or 128 KB RAM in later variants, with banked ROM/RAM in the 128K models.
  • Display: 256×192 pixel color display with an attribute grid limiting colors to 8 per 8×8 block from a 15-color palette.
  • Sound: Single-channel beeper (later models add AY-3-8912 PSG) for simple square waves and noise.

Quick reference

  • ROM folder: /userdata/roms/zxspectrum
  • Accepted formats: .tzx, .tap, .z80, .rzx, .scl, .trd, .dsk, .zip, .7z
  • Emulators: libretro: fuse, Clock Signal
  • System group: zxspectrum

BIOS

Clock Signal requires a set of Spectrum ROMs stored under /userdata/bios/ZXSpectrum/. Copy the following files so both +2/+3 and 48K/128K modes can boot:

Filename Model
plus3.rom +3 ROM
plus2.rom +2 ROM
128.rom 128K ROM
48.rom 48K ROM

RetroArch’s Fuse core does not need external BIOS files.

ROMs

Place Spectrum tapes, snapshots, or zipped collections inside /userdata/roms/zxspectrum. Fuse scans for the root .tzx/.tap/.z80 file, so keep single-game archives uncompressed or ensure the image sits at the archive root.

Emulators

libretro: fuse

Fuse exposes the standard zxspectrum. RetroArch options (videomode, shaders, pixel_perfect, etc.). Use the Quick Menu ([HOTKEY] + south) to toggle joysticks, swap palettes, or force 48K/128K behavior through the shader/input overrides.

Clock Signal

Clock Signal provides a very low-latency alternative. It uses every ROM listed above and the same ROM folder structure; enable it when you want precise input timing. The Quick Menu still controls the input assignment.

Controls & options

  • Use [HOTKEY] + south to remap the cursor keys to joysticks or to open the on-screen keyboard for text-heavy adventures.
  • When playing keyboard-driven titles, assign User 3 to Sinclair Keyboard and leave users 1–2 on joysticks to keep both keyboard and controller inputs responsive.
  • Fuse offers several joystick presets (Cursor, Kempston, Sinclair 1/2, Timex, Fuller). Pick the one that matches the game you’re launching.

Troubleshooting

  • If input conflicts occur, set User 1 to the desired joystick type and switch other users to None.
  • Some games require the full 128K ROM set; keep all four BIOS files even if you mostly play 48K releases.
  • Consult the generic support pages whenever RetroArch refuses to detect the ROM folder or if Clock Signal crashes on startup.