Research notes

A snapshot of COMMAND_LINE.md from the Earthsiege analysis. Code addresses and capture filenames refer to the research workspace; this site carries selected notes and display data.

Original executable command-line options

These are options in the supplied Earthsiege 1.0 DOS binaries, not options for our C++ program. Arguments belong to different executables; identical letters can have unrelated meanings. The executable survey finds strings, but does not by itself identify the program that consumes them.

The launcher and -eggplant

The normal entry point is ES (the installation's launcher). Its internal child-process arguments include -eggplant for the shell/simulation handoff. GO checks the complete, case-sensitive -eggplant string in 0x1272d. DBSIM also accepts only lowercase -eggplant through 0x58e74, then requires the authorization flag at startup. Its comparison branch contains an uppercase EGGPLANT string too, but the case-sensitive dispatch table has only lowercase e, so uppercase -EGGPLANT never reaches that branch. Original parser execution confirms this otherwise easy-to-miss distinction. Without that flag the programs tell the user to launch ES.

This is an internal launch handshake, not an invulnerability or cheat-mode switch. Supplying it manually does not create the mission, player and preference handoff files that DBSIM normally receives from GO. The presence of the word in the executable is not evidence of a secret gameplay command.

Why ESCD contains -B1000000

ESCD's argument tables at 0x58c8 and 0x5904 construct these movie-player calls:

playflic.exe flic\intro3.dfl -B1000000 -S83
playflic.exe flic\end.dfl    -B1000000 -S83

-B1000000 selects a 1,000,000-byte movie preload buffer. -S83 overrides movie timing to 83 milliseconds per frame, about 12.05 frames/second. Neither is a game cheat, a screen-resolution option or a general DOS memory setting. These strings are in the launcher because it passes them to PLAYFLIC.

PLAYFLIC's own embedded help names the buffer and timing options. Its parser branch 0x3ec stores the B value at 0x155fc; 0x3530 passes it to buffer constructor 0x554. That constructor allocates the smaller of the requested buffer and the movie's stored length, then uses it for streamed reads. The compiled default is 2,000,000 bytes; the launcher explicitly requests 1,000,000.

PLAYFLIC.EXE

The movie filename is the first positional argument. The parser accepts - or /, uppercase or lowercase option letters, and values attached directly to the letter. Numeric conversion is decimal.

The retained help credits Jim Kent's READFLIC example, copyright 1992, and points to the March 1993 Dr. Dobb's Journal source. The executable has adaptations for Dynamix DFL data and HMI sound. This identifies a component's ancestry; it does not mean Earthsiege's simulation was written in C rather than C++.

GO.EXE shell

0x1272d accepts - or / for the following single-letter switches and folds the letter to uppercase. It processes arguments from last to first. The special -eggplant check remains exact and case-sensitive.

DBSIM.EXE simulation

The early parser 0x58e30 handles lowercase -c for the alternate/CD path. The main parser 0x58e74 recognizes the table below. It accepts a leading -, is case-sensitive, and consumes numeric/name values in the same argument: -CHERCULES, not -C HERCULES. These are direct-program findings; forwarding every option through the outer ES launcher has not been established.

The accepted cockpit names are ROADRUNNER, GUNSLINGER, RAPTOR, TOMAHAWK, PATRIOT, PANTHER, HERCULES, COLOSSUS; the name comparison is case-insensitive. These are internal names, which differ from some displayed HERC names.

In particular, DBSIM's -B is unrelated to PLAYFLIC's -B<number>. DBSIM's branch does not parse a numeric suffix; sending it -B1000000 would merely set the debugger flag. Unknown V/W/T meanings must not be advertised as arbitrary resolution controls based on their letters alone.

Research boundary

The switch branches, stored values, movie buffer consumer and launch tables have been checked in machine instructions as well as decompiled output. tools/check_command_line.py additionally executes 34 original parser cases without launching hardware or modifying handoff files; inputs and state are in command-line.json. All four supplied tapes now have complete -p DOSBox runs, including exact input consumption and original exit files. This does not establish the unsupported development modes as useful user options. Named unknowns are retained here so future work can close them without presenting inferences as working user options. Keyboard development controls are documented separately in CHEATS_AND_DEVELOPMENT.md.

Retained VCR sidecar and development bypasses

check_vcr_sidecar.py executes original 0xbd4 in inactive, recording, equal comparison and unequal comparison states. It copies an 18-byte fixture into the record buffer, or reads/compares that fixture and sets the mismatch latch at 0x90190. The registered phase-6 consumer 0xc84 flushes recordings by reopening <tape>.dmp in append mode. The playback branch merely formats a local diagnostic string: that alone neither reports a failure nor proves a state comparison ran. There are no supplied DMP files and no direct call or embedded pointer to 0xbd4 in the inspected DBSIM image. This is a retained diagnostic facility with no verified gameplay producer in this release, not a ready-made determinism oracle. See the probe.

GO -x skips input/timer callback installation in 0x45d24, sound initialization in 0x46235, GUI callback setup in 0x1b0ff, and mouse cursor callbacks in 0x2bbbd/0x2bf15; keyboard text dispatch also tests it in 0x12be8. Cleanup 0x45a68 and main shutdown 0x12ec7 can enter debugger traps. These consumers explain its observed bypass behavior, but no supplied launch script establishes an intended standalone workflow for it.

Expansion simulator additions

The expansion main parser is 0x5ef90. Its additions are case-sensitive:

These belong to DBSIM, with the normal -eggplant handshake and existing mission handoff. They do not make the base executable high resolution, and lowercase -v is separate from uppercase -V. The tall modes are retained development paths; the captures do not establish them as supported user configurations. See SIMULATOR_VERSIONS.md for evidence and screenshots.