ioRTCW - RetroBIOS

Type	standalone
Classification	Community forks
Source	https://github.com/iortcw/iortcw
Version	unknown
Profiled	2026-10-04
Systems	return-to-castle-wolfenstein

Technical notes

Return to Castle Wolfenstein source port derived from the ioquake3 codebase and the id Software GPL release of RTCW. Ships as two separate executables: Single-player and Multiplayer, each with its own filesystem layer under SP/code/ and MP/code/.

BASEGAME is "main" for both builds. ref: SP/code/qcommon/qcommon.h:628, MP/code/qcommon/q_shared.h:62

Both builds stop with a fatal error when main/pak0.pk3 is missing, or present with a checksum other than 1886207346. A demo pak0 under demomain/ is accepted with a warning and skips the point-release check. ref: SP/code/qcommon/files.c:3842-3972, MP/code/qcommon/files.c:3836-3966

Single-player (SP/code/qcommon/files.c) then requires the four point-release paks; a missing one is fatal, a wrong checksum only prints a warning: main/sp_pak1.pk3 five localized checksums (en/fr/gm/it/sp) main/sp_pak2.pk3 3033901371, or 285968110 for the German release main/sp_pak3.pk3 five localized checksums main/sp_pak4.pk3 GOTY edition pak, 4131017020 for every language ref: SP/code/qcommon/files.c:187-225 (checksum arrays), SP/code/qcommon/qcommon.h:637-638 (NUM_ID_PAKS 6, NUM_SP_PAKS 4), SP/code/qcommon/files.c:3720-3827 (FS_CheckSPPaks)

Multiplayer (MP/code/qcommon/files.c) requires the six mp_pak files the same way: main/mp_pak0.pk3 checksum 764840216 main/mp_pak1.pk3 checksum -1023558518 main/mp_pak2.pk3 checksum 125907563 main/mp_pak3.pk3 checksum 131270674 main/mp_pak4.pk3 checksum -137448799 main/mp_pak5.pk3 checksum 2149774797 main/mp_bin.pk3 or mp_bin0.pk3 (1.51c) - VM/binary pak, optional ref: MP/code/qcommon/files.c:198-218 (mppak_checksums, binpak_checksums), MP/code/qcommon/files.c:3721-3821 (FS_CheckMPPaks)

15 files | 11 required, 4 optional | 10 in repo, 2 missing, 3 unsourceable Categories: 15 game data

pak0.pk3 required unsourceable game_data

• Path: main/pak0.pk3
• System: return-to-castle-wolfenstein
• Source: SP/code/qcommon/files.c:183-185, SP/code/qcommon/files.c:3865-3882, SP/code/qcommon/files.c:3950-3967, MP/code/qcommon/files.c:194-196, MP/code/qcommon/files.c:3859-3876, MP/code/qcommon/files.c:3944-3961
• RTCW retail base. Checksum 1886207346 in both builds; fatal when missing or when the checksum differs.

sp_pak1.pk3 required missing game_data

• Path: main/sp_pak1.pk3
• System: return-to-castle-wolfenstein
• Source: SP/code/qcommon/files.c:188, SP/code/qcommon/files.c:196, SP/code/qcommon/files.c:204, SP/code/qcommon/files.c:212, SP/code/qcommon/files.c:220, SP/code/qcommon/files.c:3735-3767, SP/code/qcommon/files.c:3806-3826
• Single-player build: fatal when missing. One checksum per language (en/fr/gm/it/sp); a mismatch prints a warning.

sp_pak2.pk3 required in repo game_data

• Path: main/sp_pak2.pk3
• System: return-to-castle-wolfenstein
• Source: SP/code/qcommon/files.c:189, SP/code/qcommon/files.c:197, SP/code/qcommon/files.c:205, SP/code/qcommon/files.c:213, SP/code/qcommon/files.c:221, SP/code/qcommon/files.c:3806-3826
• Single-player build: fatal when missing.

sp_pak3.pk3 required in repo game_data

• Path: main/sp_pak3.pk3
• System: return-to-castle-wolfenstein
• Source: SP/code/qcommon/files.c:190, SP/code/qcommon/files.c:198, SP/code/qcommon/files.c:206, SP/code/qcommon/files.c:214, SP/code/qcommon/files.c:222, SP/code/qcommon/files.c:3806-3826
• Single-player build: fatal when missing.

sp_pak4.pk3 required in repo game_data

• Path: main/sp_pak4.pk3
• System: return-to-castle-wolfenstein
• Source: SP/code/qcommon/files.c:191-192, SP/code/qcommon/files.c:199-200, SP/code/qcommon/files.c:207-208, SP/code/qcommon/files.c:215-216, SP/code/qcommon/files.c:223-224, SP/code/qcommon/files.c:3806-3826
• Single-player build: fatal when missing. GOTY edition pak, one checksum (4131017020) for every language.

mp_pak0.pk3 required missing game_data

• Path: main/mp_pak0.pk3
• System: return-to-castle-wolfenstein
• Source: MP/code/qcommon/files.c:199, MP/code/qcommon/files.c:3736-3751, MP/code/qcommon/files.c:3800-3820
• Multiplayer build: fatal when missing. A checksum mismatch prints a warning.

mp_pak1.pk3 required in repo game_data

• Path: main/mp_pak1.pk3
• System: return-to-castle-wolfenstein
• Source: MP/code/qcommon/files.c:200, MP/code/qcommon/files.c:3800-3820
• Multiplayer build: fatal when missing.

mp_pak2.pk3 required in repo game_data

• Path: main/mp_pak2.pk3
• System: return-to-castle-wolfenstein
• Source: MP/code/qcommon/files.c:201, MP/code/qcommon/files.c:3800-3820
• Multiplayer build: fatal when missing.

mp_pak3.pk3 required in repo game_data

• Path: main/mp_pak3.pk3
• System: return-to-castle-wolfenstein
• Source: MP/code/qcommon/files.c:202, MP/code/qcommon/files.c:3800-3820
• Multiplayer build: fatal when missing.

mp_pak4.pk3 required in repo game_data

• Path: main/mp_pak4.pk3
• System: return-to-castle-wolfenstein
• Source: MP/code/qcommon/files.c:203, MP/code/qcommon/files.c:3800-3820
• Multiplayer build: fatal when missing.

mp_pak5.pk3 required in repo game_data

• Path: main/mp_pak5.pk3
• System: return-to-castle-wolfenstein
• Source: MP/code/qcommon/files.c:204, MP/code/qcommon/files.c:3800-3820
• Multiplayer build: fatal when missing.

mp_bin.pk3 optional in repo game_data

• Path: main/mp_bin.pk3
• System: return-to-castle-wolfenstein
• Source: MP/code/qcommon/files.c:209, MP/code/qcommon/files.c:1596-1613
• VM/binary pak, 1.4/1.41. The client extracts game dlls only from paks whose checksum is listed.

mp_bin0.pk3 optional in repo game_data

• Path: main/mp_bin0.pk3
• System: return-to-castle-wolfenstein
• Source: MP/code/qcommon/files.c:210, MP/code/qcommon/files.c:1596-1613
• VM/binary pak, 1.51c variant.

pak0.pk3 optional unsourceable game_data
Single-player demo

• Path: demomain/pak0.pk3
• System: return-to-castle-wolfenstein
• Source: SP/code/qcommon/files.c:181, SP/code/qcommon/files.c:3858-3863, SP/code/qcommon/files.c:3933-3946, SP/code/qcommon/files.c:3969-3970
• Single-player build: a pak0 under demomain/ with checksum 2985661941 stands in for main/pak0.pk3 with a warning, and the point-release check is skipped.

pak0.pk3 optional unsourceable game_data
Multiplayer demo

• Path: demomain/pak0.pk3
• System: return-to-castle-wolfenstein
• Source: MP/code/qcommon/files.c:192, MP/code/qcommon/files.c:3852-3857, MP/code/qcommon/files.c:3927-3940, MP/code/qcommon/files.c:3963-3964
• Multiplayer build: a pak0 under demomain/ with checksum 2031778175 stands in for main/pak0.pk3 with a warning, and the point-release check is skipped.

Generated on 2026-10-10T11:26:01Z