The
gus driver provides support for the Gravis UltraSound (GUS) and GUS MAX audio cards. Both cards have on-board memory which is used for seamless playback of samples. They can play back 8- or 16-bit samples at up to 44.1kHz. They can record 8-bit samples at up to 44.1kHz. The UltraSound MAX is a full-duplex sound device, and if configured with two DRQ channels can be used for simultaneous playback and recording. The I/O port base is jumper-selected, and may be chosen from 0x210-0x260 in steps of 0x10. (The normal setting is 0x220.) The GUS takes 16 ports at its base address and 8 ports at its base address + 0x100.
The IRQ is software programmed, so you may select any IRQ from the set {3,5,7,9,11,12,15}. The DRQ lines are software programmed, and may be chosen from {1,3,5,6,7}. The drq2 field in the configuration file line specifies a second DRQ line for recording. If there is no drq2 field in the config file, the playback channel will be used for recording DMA and only half-duplex mode will be available.
The Gravis UltraSound MAX has an additional CODEC onboard which is addressed with four ports at an offset of 0x10C from the base ports (0x31C-0x36C).