Entry 16

The memory card save format

2026-09-22saveformatdecomp

Filesdocs/formats/save.md

A .hack save is the game's whole ccSaveData object written to the memory card as it sits in memory, plus a small per-slot index. Because the DWARF names every member of ccSaveData (6), the save format is known field by field without ever having looked at a real save file. The layout is on the save page.

Where it goes

ccMcard (mcard.cpp) builds every path the same way: a directory from mcDirName[volumeNum - 1] (INF SLUS_202.67:0x00306be0), a /, and a file from mcFname (0x00306d40). The four directories are BASLUS-20267DOTHACK - Infection's own product code, SLUS-20267 - and three placeholders, BASLUS-00001DOTHACK, -00002 and -00003, which read as slots reserved for the other three volumes before their product codes existed. volumeNum is 1 in the executable's data. The slot files are dhdata01 to dhdata13 (mcFname[1..13]). The slot index is written by ccMcard::SaveSys (0x001664b0) to the directory name repeated - it strcpys and then strcats the same mcDirName entry - so Infection's is /BASLUS-20267DOTHACK/BASLUS-20267DOTHACK, the usual PS2 practice of naming the main file after its directory. mcFname[0], BISLPS-00000HUCKER, is not used by SaveSys; what uses it is not known.

ccMcard::MakeDir (0x001659b0) writes /icon.sys (it builds a PS2D header) and the icon files, taking the icons from \DATA\ICON.BIN;1 through iconBinTbl (0x00306c00, twelve {offset, size} pairs) and iconName (icon10.ico, icon11.ico, icon12.ico, icon20.ico ... icon42.ico). ICON.BIN is therefore twelve PS2 icons at 90,112-byte strides, three per volume.

What is written

ccSaveSys::MainProccess (0x00171c20, a 9 KB state machine) saves in two writes (at 0x00173e10 and 0x00173e4c):

1. ccMcard::SaveSys(port, 0, info, 336) - ccSaveSys.info[12], twelve 28-byte ccSaveDataInfo slot records: status, level, clearFlag, parodyFlag, char name[18], u16 sum, int playtime.
2. ccMcard::DataWrite(port, 0, slot, saveData, 0x8530) - the whole ccSaveData object, 34,096 bytes, verbatim.

Before the second write the slot record is refreshed from the save: status 1, level and name from spcParam[0] (the player character, +0x7488), play time from +0x8400, clear and parody flags from +0x842a and +0x842b, and sum.

sum is the 16-bit sum of all 0x8530 bytes of the save data (the loop at 0x001724cc); a load compares it against the slot record at 0x001724f8 and rejects the file on a mismatch. ccSaveSys::CheckRightInfo (0x001716e0) validates all twelve records: an empty slot (status 0) must be all zeros, a used one (status 1) needs level 0-99, clearFlag 0-4, parodyFlag 0-1 and a play time below 0x0CDFE5C4 - 215,999,940 sixtieths of a second, 999:59:59.

Carrying over between volumes

ccSaveSys keeps a second array, infoPrev[12] (+0x150), with LoadInfoPrevReq and LoadDataPrevReq beside the ordinary loads: the machinery for reading the previous volume's saves. clearFlag runs 0 to 4, one per volume. In Infection, the first volume, those paths have nothing to read; how Mutation uses them is a question for that disc. ccSaveData::ConvGame (0x001752a0, sdmng.cpp) rebuilds party parameters from charTbl (in the demo overlay) and then calls LoadGame and InitTradeItem; no relocation in main or any overlay calls it, so in this build it may be dead code.

What the save holds

98 members, among them: both player names (plName, plRealName), item lists for 18 characters, trade lists, skills, growth, the mail list and its order, web news and bulletin board read flags, 160 event entries, the Chaos Gate lists and records, the keyword list (wordList[15]), 512 64-bit event flags (eventFlag, +0x54f8 - the flags ccEvent::Execute sets), area bans and protected areas, Grunty and dog counters, Data Drain counts, per-enemy kill counts and kill areas for 313 enemies, all 18 characters' parameters, play time, the pad assignment, volumes, voice and parody flags, and 250 reserved bytes.