(
Phase change
Dual disc) An earlier rewritable optical disc from Panasonic that used phase change technology. Introduced in 1995, its 5.25" cartridges held 650MB and withstood 500,000 rewrites. The PD drive also read CD-ROMs, but not Panasonic's prior phase change (PCR) disks. See
phase change disc and
optical disc.
PD Cartridge
The PD cartridges looked like and used the same technology as DVD-RAM discs. Panasonic DVD-RAM drives could also read PD discs.