Entry 199

"Infection's addresses carried to the later volumes: Image::at; the first reads of Mutation's boot"

2026-09-26volumes

Filestools/main_data.pytools/voldiff.pycrates/piney-data/src/exe.rscrates/piney-data/src/main_datacrates/piney-data/src/save/init.rscrates/piney-desktop/src/kanji.rscrates/piney-demo/src/dialog.rscrates/piney-game/src/main.rsplans/volumes.md

Phase 4 (each volume boots to its Root Town) needs to see where a later disc stops. The game refused anything but Infection. PINEY_TRY_VOLUME=1 now lets it start one anyway.

Mutation stopped at once, in ccSaveData::Init. The port read timeIdolRankDefStr at Infection's 0x0033eb90. Phase 1 had put each volume's main data in piney-data, but every reader still used Infection's addresses: in Mutation's bytes 0x0033eb90 holds something else, and its first word led nowhere. About 540 such constants sit in 80 files.

The carry

tools/main_data.py gen now also writes <volume>.carry for MUT, OUT and QUA. Each is a sorted list of (section, Infection's address, its size, the volume's address). The rows come from three sources:

• Names: every function and global whose name xfer.py carried and that is unique in its section on both sides. That is about 10,400 rows a volume.
• Votes: the globals whose names repeat, string literals' @1114 and the jump tables, by what the paired functions build at their aligned instructions. This is xfer.propagate's votes, where they agree, about 2,000 more rows. The title's "#G" (demo @1114, 0x0040eba8) lands on Mutation's 0x00421ce8, which holds "#G".
• Content: the two bitmap fonts, which have no size in Infection's symbols. They are byte for byte the same on the four discs.

Image holds the carry for the volume Image::main was made for, and the overlay's id from the PRG header (Overlay::parse, with). Image::at(inf_va) finds the row holding the address and returns the volume's address at the same offset. On Infection it returns the address unchanged. An address nothing holds comes back as 0, which no read finds. PINEY_CARRY_TRACE names each such miss.

Only constants go through at. A pointer read from the image is already the volume's. a_later_volume_carries_infections_addresses checks:

• timeIdolRankDefStr goes to Mutation's 0x00353b70, and an offset into it moves with it;
• gcmn's latticeAttributeColorTable is found through the overlay;
• an address below main's first global finds nothing.

Now carried: the save's initial strings, the fonts, and the title's memory-card dialog texts (STR_*, the two literals, saveSysMsg's entries).

Where Mutation's boot stands

It passes ccSaveData::Init and the fonts, then reaches the new game tables (NewGameTables::read). These cannot just be carried:

• Mutation's charTbl has 21 rows.
• Its NewGame fetches each record through an accessor that sends ids 18-20 to the save's 0x854-byte extension (save.md, "The extension").

voldiff.py diff NAME [--volume V] shows a function's disassembly, Infection's against the volume's, with the addresses and branch labels normalised so the two line up. It is the way to read the changed functions.