A Note about DiscoVision Discs
Due to variations in disc mastering and the mood of the mastering technician, some discs have a stronger signal than others. This can cause current players to go stupid where they simply don't know how to play the disc. Some players are capable of learning how to play these discs, and this will be documented throughout this section.
A Note about General Motors discs
DiscoVision discs produced for General Motors did not include include the Philips code. They included only the MCA codes. All LaserDisc players are capable of reading this MCA code, but have it suppressed, in favor of Philips code. This includes all players manufactured the consumer and industrial levels. The MCA DiscoVision PR-7820 is the only will LaserDisc player which can play them correctly. All current industrial players will reject the disc, due to the absence of the Philips code.
When playing a General Motors DiscoVision disc in a current LaserDisc player, you may encounter any of these problems.
|Disc will spin up, but fails to sync. Most players will abort and eject the disc.|
|Disc spins up, and eventually attains synchronization and will begin play. However, due to the absence of Philips code, the recording format is unknown as CAV or CLV and the disc will play without frame numbers or elapsed time. Search functions, still step and variable speed play will also not function.|
|Auto-Reverse players with Digital Field Memory experience a side change problem due to the absence of Philips CAV or CLV coding. Upon reaching the end of side detection, these players will try and backup to a valid frame number or time indicator do to the back-search for the digital still display. This will fail, and the player will backup through the entire side and fail to auto-reverse. This trouble only occurs when there are additional sides to play. Some players have a Film Mode which can disable the still display during side change. Enabling this feature can defeat this problem.|
Updated: July 6, 1997
Copyright ©1997 Blam Entertainment Group