Therons Quest File Formats

Theron's Quest File Formats

Theron's Quest targets the PC Engine / TurboGrafx-CD (Hudson Soft, 1992 JP / 1993 US). CPU: HuC6280 (65C02 derivative) at 7.16 MHz. Resolution: 256x224. All multi-byte values are little-endian.

Disc Layout

The game ships on a CD-ROM with the PC Engine CD-ROM System Card interface. There is no ISO 9660 filesystem — data is addressed by raw CD sector numbers.

Track	Format	Content
1	CDDA	Opening audio
2	MODE1/2352	Game code, graphics, dungeon data
3-18	CDDA	Music tracks
19	Data / ISO	Additional data

Track 02 BIN — Primary Game Data

Field	Value
JP size	8,102,640 bytes
US size	8,104,992 bytes
Sector size	2,352 bytes (raw)
User data per sector	2,048 bytes (offset 16-2063)

Raw Sector Layout

Offset  Size  Description
0x000   16    Sync/header
0x010   2048  User data
0x810   288   EDC/ECC/subheader

Boot Sequence

1. IPL loads record 0x0003E7 into local RAM at $4000
2. Stage-two CD_READ loads one sector into $3800:
   • JP: record 0x04DF
   • US: record 0x04E0
3. Payload begins with BRK $FF followed by a $0308 envelope containing a 218-entry manifest
4. Each manifest entry is 6 bytes (structural provenance, not files)

Level Envelope Format

Offset  Size  Description
0x00    2     Width (uint16 LE)
0x02    2     Height (uint16 LE)
0x04    4     Seed (uint32 LE)
0x08    2     Level index (uint16 LE)
0x0A    2     Header extension
0x0C    W*H   Grid cell data (1 byte per cell)

Grid cells use a 5-bit classification (32 possible tile values).

The game has 7 quest blocks of 262,144 bytes (0x40000) each, one per mini-dungeon.

Known startup level: seed 0x0108E938, level_index 0x0026, record 0x0B52, grid 32x27 = 864 bytes.

9-Word Descriptor Table

At US ISO offset 0x1584: nine LE uint16 words with stride 0x0400, values ranging from 0x0020 to 0x2020.

Graphics Format (4bpp Tiles)

Field	Value
Tile size	32 bytes (8x8 pixels, 4 bits/pixel)
Palette entries	16 per palette
Palette word size	2 bytes LE (9-bit HuC6260/VCE color)
Palette data size	32 bytes (16 x 2)
Max bitmap atlas	256x8 pixels

VCE 9-bit Color Format

Bit:  8-6    5-3    2-0
      GGG    RRR    BBB

3 bits per channel: blue (bits 0-2), red (bits 3-5), green (bits 6-8).

Audio Tracks (CDDA)

Tracks 1 and 3-18 are Red Book audio (44.1 kHz stereo PCM). In Firestaff's data directory these are stored as OGG Vorbis re-encodes:

File	Size	Content
TQJP01.ogg	705 KB	JP opening audio
TQUS01.ogg	218 KB	US opening audio
TQ04-TQ18.ogg	272 KB - 3.7 MB	Music tracks

Maximum queued CDDA sectors: 16.

CUE Sheets

Standard CUE format declaring track layout:

FILE "TQUS02.bin" BINARY
  TRACK 02 MODE1/2352
    INDEX 01 00:00:00

Firestaff requires exactly one TRACK 02 MODE1/2352 entry backed by a FILE "..." BINARY declaration.

System Card ROM

File	Size
syscard3.pce	262,656 bytes

The PC Engine System Card 3.0 ROM, required by CD-ROM System games. Used by Mednafen for live capture/trace support.

Save Formats

SRM — PC Engine Save Disk Format

Field	Value
Slots	5 (slot0.srm through slot4.srm)
Encoding	gzip-wrapped (DEFLATE)
Gzip magic	0x1F 0x8B 0x08
Max inflate probe	1,024 bytes

Matches the PC Engine Save Disk cartridge format. Validated via gzip framing, optional header fields, CRC32, and ISIZE.

Classification states: PRESENT_AND_RECOGNIZED, UNRECOGNIZED (non-gzip / Sphenx raw), MALFORMED (truncated gzip), ABSENT.

TQSV — Firestaff-Native Save Format

Firestaff uses its own save format for between-dungeon saves (no in-dungeon saves by design).

Path: saves/theron/slotN.tqsv

Header (64 bytes)

Offset	Size	Field
0x00	4	Magic: 0x54515220 ("TQR ")
0x04	2	Version (1)
0x06	2	Checksum (16-bit sum)
0x08	1	Quest items collected (7-bit bitmap)
0x09	1	Current dungeon ID
0x0A	1	Current dungeon state
0x0B	1	Current level (1-3)
0x0C	4	Dungeon seeds (7 x 4-bit packed)
0x10	4	Dungeon states (7 x 2-bit packed)
0x14	4	Champion gold
0x18	4	Play time (seconds)
0x1C	4	Timestamp (Unix epoch)
0x20	32	Label (null-terminated ASCII)
0x40	36	Reserved

Body: 4 champion slots x 128 bytes each (same layout as DM1 v1). Footer: 4-byte checksum. XOR obfuscation seed: 0x5A. 8 save slots total.

Media Classifications

Firestaff recognizes these disc layout variants:

Layout	Description
RAW_BIN	Standalone Track 02 BIN
ISO	Standalone ISO extract
BIN_CUE	BIN + CUE pair
ISO_OGG_CUE	ISO + OGG audio + CUE
OGG_ONLY	OGG audio files only

Verified Disc Hashes

Variant	MD5
JP Track 02 BIN	b7afb338ad31be1025b53f9aff12d73a
US Track 02 BIN	f23601102138f87c33025877767ebf76
JP Rev 1 ISO	397039af02d50d15c70b74088eb8a1cb
US ISO (concatenated)	ceb02343868f80cec899e9b239aff2da
US ISO tail only	3d8b78571dcd0e6eb8eb4b01eeb7fbba