CrocoDS

CrocoDS emulates Amstrad CPC.

About this profile

Detail	Value
Type	libretro
Classification	Official port
Source	https://github.com/libretro/libretro-crocods
Upstream	https://github.com/redbug26/crocods-core
Version	2024-10-16, stated in crocods-core/crocods.h
Revision	libretro/libretro-crocods@a9c63b294437
Profiled	2026-03-23
Profile	YAML, JSON
Cores	crocods
Systems	Amstrad CPC

Platform details

• bios_mapping:

  • source_ref: crocods-core/vga.c:185-200, crocods-core/platform.c:1024-1035
  • note: All ROMs are embedded. InitMemCPC() copies cpc6128_bin and romdisc_bin into ROMINF and ROMEXT arrays via memcpy. No filesystem lookup occurs. retro_set_environment() does not request system_directory.

• embedded_roms:

  • source_ref: crocods-core/cpc6128.bin.c (emulator code, libretro port), crocods-core/romdisc.bin.c (emulator code, libretro port)
  • note: 2 ROM sets embedded as C byte arrays: cpc6128_bin (32KB) - CPC 6128 OS (lower 16KB) + BASIC 1.1 (upper 16KB) romdisc_bin (16KB) - AMSDOS disk controller ROM, mapped to slot 7

• model_rom_map:

  • source_ref: crocods-core/vga.c:189-192
  • note: CPC 6128 only: OS in ROMINF, BASIC in ROMEXT[0], AMSDOS in ROMEXT[7] emulator_patch_ROM() applies language patches to ROMINF after loading

Technical notes

CrocoDS is an Amstrad CPC 6128 emulator ported to libretro. Supports .dsk, .sna, and .kcr file formats.

All system ROMs are compiled directly into the core binary as C byte arrays. No external BIOS files are required.

Embedded ROMs (crocods-core/):

• cpc6128.bin.c: cpc6128_bin[32768] - CPC 6128 OS (16KB) + BASIC 1.1 (16KB)
• romdisc.bin.c: romdisc_bin[16384] - AMSDOS disk controller ROM (16KB)

ROM initialization in InitMemCPC() (crocods-core/vga.c:185-200):

• ROMINF (lower ROM, 16KB): first half of cpc6128_bin (OS)
• ROMEXT[0] (upper ROM slot 0, 16KB): second half of cpc6128_bin (BASIC)
• ROMEXT[7] (upper ROM slot 7, 16KB): romdisc_bin (AMSDOS)

Called from HardResetCPC() (crocods-core/platform.c:1024-1035) using the extern byte arrays directly. No filesystem ROM loading exists in the libretro path.

A Multiface ROM loader exists (crocods-core/multiface.c:53-64) that reads LocRomMulti via fopen(), but InitMultiface() is never called from the libretro build or platform.c. Dead code in libretro context.

The core does not request retro_system_directory or declare any firmware entries in the .info file. need_fullpath is false.

Only the CPC 6128 model is emulated (no CPC 464/664 selection).

No BIOS or firmware files required.

Next steps

• Get your files, for the setup you play on
• Every system, and the files each one needs
• When a game does not start

Data as of 4 November 2026.