z3ed Doctor Commands

The doctor command suite provides diagnostic and repair tools for ROM data integrity. All commands support structured JSON output for automation.

Available Doctor Commands

Command	Description
overworld-doctor	Diagnose/repair overworld data (tile16, pointers, ZSCustom features)
overworld-validate	Validate map32 pointers and decompression
dungeon-doctor	Diagnose dungeon room data (objects, sprites, chests)
rom-doctor	Validate ROM file integrity (header, checksums, expansions)
rom-compare	Compare two ROMs for differences

Common Flags

All doctor commands support:

• --rom <path> - Path to ROM file (required)
• --format json|text - Output format (default: text)
• --verbose - Show detailed output

overworld-doctor

Diagnose and repair overworld data corruption.

# Basic diagnosis
z3ed overworld-doctor --rom zelda3.sfc
 
# Compare against vanilla baseline
z3ed overworld-doctor --rom zelda3.sfc --baseline vanilla.sfc
 
# Apply fixes with dry-run preview
z3ed overworld-doctor --rom zelda3.sfc --fix --output fixed.sfc --dry-run
 
# JSON output for agents
z3ed overworld-doctor --rom zelda3.sfc --format json

Detects

• ZSCustomOverworld version (Vanilla, v2, v3)
• Expanded tile16/tile32 regions
• Expanded pointer tables (tail map support)
• Tile16 corruption at known problem addresses
• Map pointer validity for all 160+ maps

dungeon-doctor

Diagnose dungeon room data integrity.

# Sample key rooms (fast)
z3ed dungeon-doctor --rom zelda3.sfc
 
# Analyze all 296 rooms
z3ed dungeon-doctor --rom zelda3.sfc --all
 
# Analyze specific room
z3ed dungeon-doctor --rom zelda3.sfc --room 0x10
 
# JSON output
z3ed dungeon-doctor --rom zelda3.sfc --format json --verbose

Validates

• Room header pointers
• Object counts (max 400 before lag)
• Sprite counts (max 64 per room)
• Chest counts (max 6 per room for item flags)
• Object bounds (0-63 for x/y coordinates)

Sample Output (Text)

╔═══════════════════════════════════════════════════════════════╗
║                    DUNGEON DOCTOR                             ║
╠═══════════════════════════════════════════════════════════════╣
║  Rooms Analyzed: 19                                           ║
║  Valid Rooms: 19                                              ║
║  Rooms with Warnings: 0                                       ║
║  Rooms with Errors: 0                                         ║
╠═══════════════════════════════════════════════════════════════╣
║  Total Objects: 890                                           ║
║  Total Sprites: 98                                            ║
╚═══════════════════════════════════════════════════════════════╝

rom-doctor

Validate ROM file integrity and expansion status.

# Basic validation
z3ed rom-doctor --rom zelda3.sfc
 
# Verbose with all findings
z3ed rom-doctor --rom zelda3.sfc --verbose
 
# JSON output for CI/automation
z3ed rom-doctor --rom zelda3.sfc --format json

Validates

• SNES header (title, map mode, country)
• Checksum verification (complement XOR checksum = 0xFFFF)
• ROM size (vanilla 1MB vs expanded 2MB)
• ZSCustomOverworld version detection
• Expansion flags (tile16, tile32, pointer tables)
• Free space analysis in expansion region

Sample Output (Text)

╔═══════════════════════════════════════════════════════════════╗
║                      ROM DOCTOR                               ║
╠═══════════════════════════════════════════════════════════════╣
║  ROM Title: THE LEGEND OF ZELDA                               ║
║  Size: 0x200000 bytes (2048 KB)                               ║
║  Map Mode: LoROM                                              ║
║  Country: USA                                                 ║
╠═══════════════════════════════════════════════════════════════╣
║  Checksum: 0xAF0D (complement: 0x50F2) - VALID                ║
║  ZSCustomOverworld: Vanilla                                   ║
║  Expanded Tile16: NO                                          ║
║  Expanded Tile32: NO                                          ║
║  Expanded Ptr Tables: NO                                      ║
╚═══════════════════════════════════════════════════════════════╝

rom-compare

Compare two ROMs to identify differences.

# Basic comparison
z3ed rom-compare --rom my_rom.sfc --baseline vanilla.sfc
 
# Show detailed byte differences
z3ed rom-compare --rom my_rom.sfc --baseline vanilla.sfc --show-diff
 
# JSON output
z3ed rom-compare --rom my_rom.sfc --baseline vanilla.sfc --format json

Diagnostic Schema

All doctor commands produce findings with consistent structure:

{
  "findings": [
    {
      "id": "tile16_corruption",
      "severity": "error",
      "message": "Corrupted tile16 at 0x1E878B",
      "location": "0x1E878B",
      "suggested_action": "Run with --fix to zero corrupted entries",
      "fixable": true
    }
  ],
  "summary": {
    "total_findings": 1,
    "critical": 0,
    "errors": 1,
    "warnings": 0,
    "info": 0,
    "fixable": 1
  }
}

Severity Levels

• info - Informational, no action needed
• warning - Potential issue, may need attention
  
• error - Problem detected, should be fixed
• critical - Severe issue, requires immediate attention

Agent Usage

For AI agents consuming doctor output:

# Get structured JSON for parsing
z3ed rom-doctor --rom zelda3.sfc --format json
 
# Chain with jq for specific fields
z3ed rom-doctor --rom zelda3.sfc --format json | jq '.checksum_valid'
 
# Check exit code for pass/fail
z3ed rom-doctor --rom zelda3.sfc --format json && echo "ROM OK"