1 · The anatomy of a real unit script

Here is the opening of tsfat.bos (an armored tank — the same script class as retail AMPH), exactly as the modder left it:

#define TA                          // This is a TA script
#include “sfxtype.h”
#include “exptype.h”
piece  base, body, track1, track2, turret, barrel, flare1;
static-var  restore_delay, poo;
// Signal definitions
#define SIG_AIM        2
RockUnit(anglex, anglez)
{
turn base to x-axis anglex speed <50.010989>;
turn base to z-axis anglez speed <50.010989>;
wait-for-turn base around z-axis;
wait-for-turn base around x-axis;
turn base to z-axis <0.000000> speed <20.000000>;
turn base to x-axis <0.000000> speed <20.000000>;
}

Three things are immediately different from how we reconstructed retail AMPH:

• Angle literals: <50.010989> — degrees in angle brackets. The compiler converts them to BAM (the game's 65536-units-per-turn angles) at compile time. <50.010989> compiles to 9101 in the shipped COB — the same ~9100 range as retail AMPH's RockUnit speed (9100). Distances use [4.2]-style brackets (elmo), and everything else is raw.
• Named signals: #define SIG_AIM 2 instead of a bare signal 2. Same bytecode.
• The human residue: static-var restore_delay, poo; — the second static is literally named poo. Real code has leftovers.

And the aiming core is the textbook pattern verbatim:

AimPrimary(heading, pitch)
{
    signal SIG_AIM;
    set-signal-mask SIG_AIM;
    turn turret to y-axis heading speed <35.005495>;
    turn barrel to x-axis <0.000000> - pitch speed <15.000000>;
    wait-for-turn turret around y-axis;
    wait-for-turn barrel around x-axis;
    start-script RestoreAfterDelay();
    ...
}

The <0.0> - pitch inversion, the signal dance, the restore thread — this is Cavedog's STDTANK.H AimPrimary with the same two turn speeds. That is no coincidence: the constants match our retail decode exactly. Retail AMPH's compiled aim speeds are 6370 and 2730 BAM; here the source says <35.005495> and <15.000000> degrees. Convert: 35.005495° × 65536/360 = 6372.5, and 15° × 65536/360 = 2730.7 — the shipped COB carries 6371 and 2730. The modder took the standard header's values, and the conversion factor 65536/360 that we derived from bytecode in the AMPH article is confirmed by independent source code.

2 · The three patterns in the wild

The aim/fire vehicle (tsfat, tsffav, tsflt)

RockUnit/HitByWeapon → Create (hide flare) → SetMaxReloadTime/RestoreAfterDelay → Aim*/Fire*/Query*/AimFrom* → Killed ladder. This is the AMPH class — and the mod's versions are near-identical to retail, differing in speed constants and names.

The deploy/state-machine factory (tsfcv, tsfvp, tsfsy, tsfasf)

These carry Cavedog's state-machine idiom, which the retail scripts also use: InitState, RequestState, Go/Stop, plus activatescr/deactivatescr or OpenYard/CloseYard pairs. The busy-flag + wanted-state pattern (while (state != wanted) sleep) is written out longhand in every one of them — the code is copied between mods, exactly like real software.

The walking commander (tsfcom)

21 scripts, ~107 motion operations: walk/walklegs/MotionControl for the gait, aim/fire on top, and a factory hook. The gait is the same while (moving) loop family as retail walkers, split over two scripts (transition stride + loop runner) — the pattern our animation pipeline learned to recognise the hard way.

3 · The modern dialect: detecthack()

Then there is this, at the top of tsfcom.bos — an anti-hack probe that has nothing to do with animating a mech:

detecthack()
{
    sleep rand(500,5000);
    var unit_ID, numbcared;
    var max, min;
    max = get MAX_ID;
    min = get MIN_ID;
    var myteam;
    myteam = get UNIT_TEAM(get MY_ID);
    numbcared=0;
    while(1)
    {
        numbcared=0;
        for (unit_ID = min; unit_ID <= max; ++unit_ID)
        {
            if (get UNIT_XZ(unit_ID) == get PIECE_XZ(base))
            {
                if (get UNIT_HEIGHT(unit_ID) == [4.2])
                {
                    ++numbcared;
                }
            }
        }
        ...

This is a different BOS language level than the Cavedog scripts: local var declarations, for/while(1) loops, ++, rand(a,b), and get with parameters (engine values per unit: UNIT_TEAM(unit), UNIT_XZ(unit), PIECE_XZ(piece)). It scans every unit on the map and checks whether something with the commander's exact position and a specific height exists — a map-hack/game-hack detector, likely counted and reported via a unit value.

It compiles because the modder used a compiler with the extended syntax (the community ggs/BASM line advertises "inlineable functions", AND/OR/XOR keywords and Scriptor compatibility). The bytecode side is the same stack machine: rand is 0x10041000, and the parameterised get is the getuv family (0x10042000) our opcode table lists next to plain get.

4 · Round-trip on third-party code

The strongest check for any decode is recompilation. We compiled the mod's own tsfat.bos with the community toolchain (BOS to BASM v0.82 + BASM 0.8.1.1, under Wine) and compared the result against the tsfat.cob the mod itself shipped:

Meaning: our opcode semantics, operand order, and literal conversions are not just self-consistent — third-party source, third-party bytecode and our decoder all agree. This is the same conclusion as the AMPH round-trip (retail code, retail COB), now from a second, independent codebase.

5 · What mod code teaches decoders

• The literal forms are part of the language: <deg> for angles (compiled × 65536/360), [elmo] for distances (× 65536), bare numbers for raw values and milliseconds. A decoder that treats all three as "a number" will be off by 182× or 65536× on some scripts.
• Patterns travel by copy-paste: aim/fire/restore, the state machine, the gait loop — recognising the family from 3 script names beats reading 200 lines of bytecode. That is exactly the routing rule our animation pipeline uses.
• Sources can disagree with shipped COBs by tiny constants. A 1–6 BAM delta is a compiler rounding artifact, not a decode error — when reconciling source against bytecode, compare structure first and treat angle constants within ±10 BAM as equal.
• Modern dialect scripts exist in the wild (var, for, rand, parameterised get). A toolchain that only speaks the retail dialect will reject real mods; the community compilers speak both.
• Not every COB carries a compiler signature. The presence of "Build by COBBLER" is a fact about that compiler, not about the format.

6 · The material, browsed

All 24 .bos sources, the compiled .cob files and tsf weapons.tdf are extracted and preserved in our working archive; the mod zip itself is on the downloads page. Two of these units are already live as COB-exact previews: TSFAT and TSFCOM.

7 · Credits

The Secret Forces team (the mod, its scripts and models) — rights remain with them; preserved here for study. Cavedog Entertainment — BOS, the standard headers, the engine. ggs & Mafia — the compiler toolchain whose registries and round-trip made this article testable. Related: the retail AMPH decode and the toolchain archive.