grouping four oscillators per voice, for a limit of seven-voice audio). The IIGS is often referred to as a 15-voice system, because one voice, or "sound generator" consisting of two oscillators, is always reserved as a dedicated clock for the sound chip's timing interrupt generator. Software that does not use the system firmware, or uses custom-programmed tools (certain games, demos and music software), can access the chip directly and take advantage of all 32 voices. The computer's audio capabilities were given as the primary reason for record label Apple Corps's 1989 resumption of legal action against Apple that had been previously suspended. Apple Corps claimed that the IIGS's audio chip violated terms of the 1981 settlement with the company that prohibited Apple, Inc. from getting involved in the music business. A standard -inch headphone jack is on the back of the case, and standard stereo computer speakers can be attached there. This jack provides only monaural sound and a third-party adapter card is required for stereo, despite that the Ensoniq and virtually all native software produces stereo audio. The Ensoniq can drive 16 speaker output channels, but the molex expansion connector Apple provided only allows 8. There is 64 KB of dedicated memory (DOC-RAM) on the IIGS motherboard, separate from system memory, for the Ensoniq chip to store its sampled wavetable instruments. To exploit the IIGS's audio capabilities, during its introduction, Apple sold Bose Roommate amplified speakers for the computer (matching its platinum color and with custom Bose/Apple logo grille covers). Expansion Like other Apple II machines before it, the IIGS is highly expandable. The expansion slots can be used for a variety of purposes, greatly increasing the computer's capabilities. SCSI host adapters can be used to connect external SCSI devices such as hard drives and a CD-ROM drive. Other mass-storage devices such as adapters supporting more recent internal 2.5-inch IDE hard drives can also be used. Another common class of Apple IIGS expansion cards is accelerator cards, such as Applied Engineering's TransWarp GS, replacing the computer's original processor with a faster one. Applied Engineering developed the PC Transporter, which is essentially an IBM-PC/XT on a card. A variety of other cards were also produced, including ones allowing new technologies such as 10BASE-T Ethernet and CompactFlash cards to be used on the IIGS. Development Steve Wozniak said in January 1985 that Apple was investigating the 65816, and that an 8