CD-ROM normally expressed with binary prefixes, subtracting the space used for error correction data. A standard 120 mm, "700 MB" CD-ROM can actually hold about 737 MB (703 MiB) of data with error correction (or 847 MB total). In comparison, a single-layer DVD-ROM can hold 4.7 GB of error-protected data, more than 6 CD-ROMs. CD-ROM discs are read using CD-ROM drives. A CD-ROM drive may be connected to the computer via an IDE (ATA), SCSI, SATA, FireWire, or USB interface or a proprietary interface, such as the Panasonic CD interface, LMSI/Philips, Sony and Mitsumi standards. Virtually all modern CD-ROM drives can
Philips PM5544 the most commonly used test cards, with only the SMPTE bars, the BBC Test Card F and the Snell & Wilcox Zone Plate coming close to its usage. The Philips Pattern was later incorporated into other test pattern generators from Philips themselves, as well as test pattern generators from various other manufacturers. The BBC occasionally used a slightly modified version called Test Card G from 1971 until the late-1990s in conjunction with Test Card F, and although it was also used by the IBA in the 1970s it eventually abandoned the Test Card G and developed its own test card