Optical disc drive operations, and the last speed for read-only (ROM) operations. For example, a 40×/16×/48× CD writer drive is capable of writing to CD-R media at speed of 40× (6,000 KB/s), writing to CD-RW media at speed of 16× (2,400 KB/s), and reading from a CD-ROM media at speed of 48× (7,200 KB/s). During the times of combo (CD-RW/DVD-ROM) drives, an additional speed rating (e.g. the 16× in 52×/32×/52×/16×) is designated for DVD-ROM media reading operations. For DVD writer drives, Blu-ray disc combo drives, and Blu-ray disc writer drives, the writing and reading speed of their respective optical media are specified in
Picture disc unhappy with their quality and soon began making an improved type. A rigid blank shellac core disc was sandwiched between two illustrated sheets and each side was then topped with a substantial layer of high-quality clear plastic into which the recording was pressed. Like nearly all records being made for the general public, they were recorded at 78 rpm, but one issue was recorded at 33⅓ rpm, a speed already in use for special purposes which Victor was then unsuccessfully attempting to introduce into home use. It was the first 33⅓ rpm picture disc and the only one made until