NAME    [Toc]    [Back]

     gus - Gravis UltraSound/UltraSound MAX device driver

SYNOPSIS    [Toc]    [Back]

     gus0 at isa? port 0x220 irq 7 drq 1 drq2 6
     gus* at isapnp?
     audio* at gus?

DESCRIPTION    [Toc]    [Back]

     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).

SEE ALSO    [Toc]    [Back]

     audio(4), intro(4), isa(4), isapnp(4)

REFERENCES    [Toc]    [Back]

     Gravis  UltraSound  Low-Level Toolkit, Revision 2.01, 20 May
1993, published
 by Advanced Gravis and Forte Technologies.

     If you wish to use wdc(4) on the ISAPNP version of the card,
and it comes
     up as DISABLED, Gravis has a PNPCFG.EXE program which re-enables it.

HISTORY    [Toc]    [Back]

     The gus device driver appeared in NetBSD 1.1.

BUGS    [Toc]    [Back]

     The full-duplex features of the GUS MAX have not been  fully
tested, and
     full-duplex  on the original GUS may not be possible at all.

     Only two voices on the GF1 synthesizer chip are used by this
driver (for
     left and right channels).

     Manipulating  the  mixer while audio samples are playing can
lead to device
     driver confusion (and maybe even a system panic).

     Manipulating the mixer device seems to create pregnant  system pauses,
     probably due to excessive interrupt masking.

     The joystick and MIDI port interfaces are not supported.

OpenBSD      3.6                         November     4,     1995