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RetroBIOS

FBZX

FBZX emulates Sinclair ZX Spectrum.

About this profile
Detail Value
Type standalone
Classification Other
Source https://github.com/rastersoft/fbzx
Version 3.9.1
Revision rastersoft/fbzx@8d6b4cbe5fec
Profiled 2026-10-20
Profile YAML, JSON
Cores fbzx
Systems Sinclair ZX Spectrum
Technical notes

ZX Spectrum emulator for SDL by Sergio Costas. Emulates the 48K, the 128K, the Amstrad +2, the +2A/+3 and the Spanish 128K, with Interface 1 and microdrives. The GitHub tree stops at 3.9.1 plus two commits, the last one pointing at the project's move to GitLab. RetroPie builds this head on x86 and the 2.11.1 tag (fc1da080a17c400d8f9fdc316cbe8c1362a371c9) elsewhere. 2.11.1 is the C code base that 3.x rewrote in C++, and its ROM loader opens the same names in the same order with the same fallbacks. ref: src/emulator.cpp:49-160, and lines 63-195 of the tag's emulator.c

Every ROM is opened through myfopen, which tries the relative path from the working directory, then under /usr/share, then under /usr/local/share. make install copies the ROMs the project ships to share/spectrum-roms, and RetroPie starts the emulator from inside $md_inst/share so the relative path resolves there. ref: src/llscreen.cpp:113-133, Makefile:30-34

A reset loads the ROM set of the current model, read in 16 KiB pages, and a missing page ends the program with "Can't load file". The model is the 48K unless the configuration file or the machine menu picks another one, and a snapshot can switch it too. The Interface 1 ROM is loaded after every model and its absence also ends the program. ref: src/computer.cpp:53,186, src/emulator.cpp:68-158,308-326, src/cargador.cpp:593-599

The +2A/+3 model tries plus3-41-0.rom to plus3-41-3.rom (ROM 4.1) first, then plus3-40-0.rom to plus3-40-3.rom (ROM 4.0), then the legacy names plus3-0.rom to plus3-3.rom. The project ships only the legacy names, holding the 4.0 ROM. ref: src/emulator.cpp:103-134

fbzx/keymap.bmp, installed to share/fbzx, is the keyboard picture shown from the help menu, and its absence only shows "Keymap picture not found". ref: src/menus.cpp:1761, src/llscreen.cpp:486-498

Files

Section titled “Files”

0 files: 0 required, 0 optional. 12 more files come with the app.

File Hash
spectrum-roms/48.rom MD5 4c42a2f07521
spectrum-roms/128-0.rom MD5 b4d2692115a9
spectrum-roms/128-1.rom MD5 6e09e5d3c4ae
spectrum-roms/plus2-0.rom MD5 4ed7af463630
spectrum-roms/plus2-1.rom MD5 b3db95931cc8
spectrum-roms/plus3-0.rom MD5 9833b8b73384
spectrum-roms/plus3-1.rom MD5 0f711ceb5ab8
spectrum-roms/plus3-2.rom MD5 3b6dd659d5e4
spectrum-roms/plus3-3.rom MD5 a148bcc575e5
spectrum-roms/128-spanish-0.rom MD5 c1231a70b812
spectrum-roms/128-spanish-1.rom MD5 4f341936594c
spectrum-roms/if1-2.rom MD5 31b704ae9253

Comes with the app

Section titled “Comes with the app”
12 files

48.rom comes with the app

ZX Spectrum 48K ROM

  • Default model, loaded at the first reset.

128-0.rom comes with the app

ZX Spectrum 128K ROM 0

128-1.rom comes with the app

ZX Spectrum 128K ROM 1

plus2-0.rom comes with the app

Amstrad +2 ROM 0

plus2-1.rom comes with the app

Amstrad +2 ROM 1

plus3-0.rom comes with the app

Spectrum +3 ROM 4.0, page 0

  • Size: 16.0 KB
  • SHA1: e319ed08b4d53a5e421a75ea00ea02039ba6555b
  • MD5: 9833b8b73384dd5fa3678377ff00a2bb
  • CRC32: 17373da2
  • Aliases: plus3-40-0.rom
  • Read under plus3-40-0.rom before the legacy name.

plus3-1.rom comes with the app

Spectrum +3 ROM 4.0, page 1

  • Size: 16.0 KB
  • SHA1: c9969fc36095a59787554026a9adc3b87678c794
  • MD5: 0f711ceb5ab801b4701989982e0f334c
  • CRC32: f1d1d99e
  • Aliases: plus3-40-1.rom

plus3-2.rom comes with the app

Spectrum +3 ROM 4.0, page 2

  • Size: 16.0 KB
  • SHA1: 22e50c6ba4157a3f6a821bd9937cd26e292775c6
  • MD5: 3b6dd659d5e4ec97f0e2f7878152c987
  • CRC32: 3dbf351d
  • Aliases: plus3-40-2.rom

plus3-3.rom comes with the app

Spectrum +3 ROM 4.0, page 3

  • Size: 16.0 KB
  • SHA1: 65f031caa8148a5493afe42c41f4929deab26b4e
  • MD5: a148bcc575e51389e84fdf5d555c3196
  • CRC32: 04448eaa
  • Aliases: plus3-40-3.rom

128-spanish-0.rom comes with the app

Spanish 128K ROM 0

128-spanish-1.rom comes with the app

Spanish 128K ROM 1

if1-2.rom comes with the app

Interface 1 ROM, second edition

  • Size: 8.0 KB
  • SHA1: 5cfb6bca4177c45fefd571734576b55e3a127c08
  • MD5: 31b704ae925305e74f50699271fddd9a
  • CRC32: bb66dd1e
  • Aliases: if1-v2.rom
  • Loaded after every model, if1-v2.rom being the legacy name tried next.

Next steps

Section titled “Next steps”
.

Maintained by Abdess on GitHub. Report a problem.

Packs from release v2026.10.10, .

MIT for the tooling and metadata. BIOS and firmware files are third-party system software, preserved for personal backup, archival and interoperability.