杏吧原创

Europeans dreading those all-night sittings to watch the Sydney Olympics will
now be able to record 12 hours of the events on a single video tape. JVC, the
inventor of VHS, developed an extended-play (EP) mode for countries using the
PAL TV system. Current PAL VCRs run a 4-hour tape at 23.4 millimetres per second
in standard-play mode to record 4 hours and 11.7 mm/s in long-play mode to
record 8 hours. In new EP mode, the tape runs at a mere 7.8 mm/s to give 12
hours. The trick is to reduce the width of the helical tracks and use improved
noise-reduction circuitry to deliver acceptable pictures and sound.