Entry 24

Event scripts on every volume, and how a save carries into the next

2026-09-23scriptsavevolumestest

Filestools/evscript.pytools/test_evscript.pytools/save.pytools/test_save.pydocs/engine/events.mddocs/formats/save.md

18 decoded Infection's event scripts and 16 its save. Both leaned on the symbol table. This entry makes both work from each volume's own code and follows a save from one volume into the next. The work was done by a helper agent; I re-ran its checks and read the key sites. The reference is on the events page and the save page.

Event scripts without symbols

tools/evscript.py no longer uses Infection's addresses:

• It finds Execute's, CheckOpen's and SetCurrentOpen's switches from their code: the sltiu bound, the default branch, the jump table and the jr.
• It measures each case's operand count by running that case in eemu.
• It takes script and message extents from the gaps between arrays. On Infection this reproduces every script name and size and all 170 message symbols.

evscript.py check then walks every script with the volume's own interpreter: 0 mismatches on all four. I re-ran it on MUT: 167 Execute cases, 40 conditions, 12 tags, 196 scripts.

The interpreter grows by one case per volume (166, 167, 167, 168):

• Opcode 99 gains an operand from MUT on: a noise level.
• Opcode 168 (MUT on) sends mail 324 once any town has all three Grunty types grown up.
• Opcode 169 has a case only in Quarantine (QUA SLUS_205.64:0x001c52e8). Outbreak's copy of the ending script already contains the opcode, and its interpreter skips it.

Opcode 169 answers 23's question of what Quarantine loads KFED.BIN for:

• It loads KFED.BIN and KFAED.BIN into two $gp globals.
• It adds the ending.ccs file list and runs gcmn 0x004f0a30, a routine that starts a thread and waits for it.
• Then it frees both buffers.

I scanned every code word of main and the four overlays for accesses to those two globals. The only ones are the case's own two stores and the two loads that pass the buffers to ccFree. So the thread does not reach them through those globals; whether it reaches them another way is not traced.

Other behaviour changes are listed on the events page:

• fade resets first;
• call_lock clears more bits;
• staff_roll grants wallpapers in OUT and QUA;
• character accessors reach the three new party members.

QUA adds seven ML events and shares its other 199 scripts byte for byte with OUT. Each volume's first story event opens on event_done 100·(v−1).

The save across volumes

tools/save.py runs each volume's own ccSaveSys and ccMcard code in eemu, against a memory card kept in Python. So paths, sizes, sums and copies are whatever the game does.

The main differences from 16:

• Slot files are dhdata01..12, not ..13. MakeDir writes twelve, and only mcFname+4 is referenced.
• From Mutation on, a slot is 0x8d84 bytes. ccSaveData is still 0x8530 on every volume, with the same member offsets. A 0x854-byte extension follows it, holding the lists, parameters and counters of the three new party members (Tsukasa, Subaru, Sora, charTbl rows 18-20). The constructor allocates it (MUT SLUS_205.62:0x00175650), and accessors route ids 18-20 there.
• Each volume has its own directory (BASLUS-2056xDOTHACK) and three icons. Mutation's mcDirName finally fills in the three later directories that Infection had as placeholders.

The carry-over, which save.py carry --prev runs end to end:

1. The title screen offers the previous volume's saves when one has clearFlag >= volumeNum - 1.
2. LoadInfoPrevReq reads the previous volume's index. MUT reads Infection's, OUT reads MUT's, QUA reads OUT's.
3. LoadDataPrevReq reads the slot into ccSaveData at the same offsets. Mutation leaves its extension zeroed, since Infection has none. OUT and QUA copy the previous extension as it is.
4. ccThDemo calls ccStartEventConvert, which marks event 100·(volumeNum−1) done, then ConvGame. ConvGame resets every character not in the party to its charTbl row, reloads names and settings, clears the trade lists, and sets newGameFlag to 2.

I ran INF→MUT and MUT→OUT. In both, the saved bytes load back identical apart from padding. For INF→MUT the trace shows the three copy ranges and the untouched extension.

Correction to 16: ConvGame is reachable. Infection's ccThDemo calls it at INF demo.prg:0x00400b2c, right after ccStartEventConvert at 0x00400b20, which I read myself. The previous-volume path runs in Infection too: volumeNum - 1 = 0 is replaced by 1, so it loads its own directory and marks event 0 done.

tools/test_evscript.py and tools/test_save.py cover every extracted volume and skip the rest.