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 from the late 1940s through the 1950s. Their most popular and well-known issues resembled Vogue records in their general style of illustration and use of high-quality materials, but they were only 7 inches in diameter, had no reinforcing core disc, and sold for a much lower price. Other companies such as Voco also made picture discs for children. Red Raven Movie Records, introduced in 1956, were a very unusual type of children's picture disc. They featured a sequence of sixteen interwoven animation frames arrayed around the center and were to be played at 78 rpm on a turntable with a