(CD-ROM eXtended Architecture) A CD-ROM format enhancement introduced in 1988 by Philips, Sony and Microsoft that helps to synchronize text, audio and video more accurately on multimedia discs. The original CD-ROM format is known as Mode 1, and XA is known as Mode 2. There are two sector formats in XA: Mode 2 Form 1 contains all the error correction as in Mode 1. This mode is sometimes the default for CD-R authoring programs, because it provides more compatibility with multisession discs. Mode 2 Form 2 eliminates one level of error correction to make more room on the disc for multimedia data.CD-ROM XA functions as a bridge between CD-ROM and CD-I as CD-ROM XA discs will play on a CD-I player. CD-ROM XA supports the ADPCM audio compression method and provides up to 9.5 hours of AM-quality stereo or 19 hours of monophonic audio. See CD-I.