CD-ROM and CD32 Development Tools

The 1993 International Amiga Developers Conference notes document the CD-ROM mastering toolchain (ISOCD, OptCD, SimCD) and CDTV/CD32 development practices. These tools are in the CD32/ directory of the Developer CD.

The CD-ROM mastering toolchain

Three tools work together: OptCD gathers access statistics → ISOCD creates optimized ISO-9660 images → SimCD tests without pressing discs.

Tool Location Purpose
ISOCD CD32/ISO9660Tools_V1.04/ISOCD Create ISO-9660 disc images
OptCD CD32/ISO9660Tools_V1.04/OptCD Monitor access patterns for optimization
SimCD CD32/ISO9660Tools_V1.04/SimCD Simulate CD-ROM from hard drive partition
BuildCD CD32/BuildCD/BuildCD-1.33 Create bootable CD32/CDTV discs

ISOCD — disc image creation

ISOCD examines a directory or partition and creates a standard ISO-9660 image ready for mastering. The image works on Macintosh, Unix, IBM PC, and CDTV/CD32.

Key features: - File access optimization — reorders files based on OptCD statistics to minimize CD-ROM seek time (the primary bottleneck). - CDTV.TM trademark file — placed near the disc beginning; required for CDTV compatibility. ISOCD inserts it automatically. - Custom CDFS options — configurable file system parameters. - Ordered file layout — files can be arranged in access-order rather than alphabetically, dramatically reducing average seek time. - Primary Volume Descriptor — ISO-9660 header area for disc metadata.

OptCD — access pattern monitoring

OptCD monitors real-world CD0: access patterns and collects statistics: - Which files are read most frequently - The order in which files are accessed - Seek distances between reads

This data feeds ISOCD's optimization algorithm.

SimCD — testing without pressing

SimCD treats a hard drive partition as if it were a CDTV CD0: drive. Use ISO-9660 images created by ISOCD for realistic testing without pressing actual discs.

Important: have more than twice the free space of the intended ISO image — ISOCD needs workspace during image creation.

CD-ROM seek time optimization

CD-ROM seek time is the critical performance bottleneck. Unlike hard drives, CD head movement is slow (100-500ms typical seek). Strategies:

  1. Place frequently-accessed files near the disc beginning — reduces maximum seek distance.
  2. Cluster related files — files accessed in sequence should be physically adjacent.
  3. Use OptCD data — real-world access patterns beat guesses.
  4. Minimize seeks between data streams — for multimedia (CDXL video + audio), interleave data.
  5. Test with SimCD — measure actual performance before pressing.

CDTV/CD32 boot process

  1. ROM BIOS loads (CD32 has its own ROM; CDTV has CD-I style ROM)
  2. Boot code reads the ISO-9660 image's boot section
  3. CDFS (CD-ROM File System) mounts the disc
  4. system-configuration loads from CD
  5. startup-sequence executes from CD
  6. Application launches

The CDTV.TM file must be present on the disc for CDTV compatibility. ISOCD places it near the beginning automatically.

Additional CD32 development resources

The 1993 DevCon also covered:

  • MPEG and the Amiga/CDTV — MPEG video playback on CD32 hardware
  • CDTV programming and Spooly Device — CD32-specific APIs
  • Retargetable Graphics specification — RTG for non-Amiga display hardware
  • DSP on the Amiga — DSP audio processing
  • MediaDevices — unified multimedia device interface
  • A1200/A600 PCMCIA — PCMCIA slot hardware development notes
  • 68060 overview — fourth-generation 68k CPU

See Also

Sources: Commodore-Amiga, Inc., 1993 International Amiga Developers Conference Notes. Raw: raw/cd32/cdrom-dev-conference-1993.md Updated: 2026-08-04