GROM Optical Drive

GROM’s is a MiniDVD-ROM based format, design reflects the unique demands of arcade hardware, where reliability, speed, and protection against tampering are critical. Unlike standard consumer disc formats, it integrates tightly with the system’s disc controller, allowing for controlled data access and efficient streaming. The use of DI protocol scrambling and DVD key–based encryption helps prevent unauthorized copying, while XA-DPCM audio streaming enables consistent, low-latency playback directly from the disc.

GROM discs are validated through multiple integrity checks, including verification of six BCA marks, data frame formatting, and a Media ID located in the lead-in area. The format also uses a custom disc layout, with sectors that are both scrambled and protected by an encrypted logo stored in the initial sectors.

At the hardware level, the optical disc controller ASIC runs firmware developed using ARM Development Suite v1.2. It operates over the DI protocol and is stored on-chip, utilizing 128KB of ROM and 4KB of RAM.