SOUND BOARD CHIPSET: VARIOUS MODELS
by OPTi

Phone:
408-486-8000
Fax:
408-486-8001
BBS:
408-486-8555
e-mail:
OPTiMedia@opti.com
Web:
www.opti.com
Type:
Varies
OS/2 Drivers:
Available, IBM's MPU-401 driver needed for wavetable
Drivers from:
BBS, OS/2 ftp: 929_v2.zip or opti928.zip; IBM's MPU-401 driver; also see ftp://ftp.opti.com/pub/multimed/
Boards using this chipset include:
someReveal boards, Diamond MMK4000's sound board, MediaMagic
Comments (925):
The OPTi web site did not have an entry for OS/2 drivers for their 925 chipset, but I've received one report that it works fine with the 924 drivers.
Comments (928 & 929):
OPTi sells a sound board design to other companies, and also sells this design themselves under the "MAD16" name. The 929_v2.zip (aka opti928.zip) driver is a version 2.0 driver which adds official support for Windows sound and which activates the 929 board's MPU-401 port, officially for use with Windows. While at least one beta version of IBM's MPU-401 driver worked well with this feature, the release version does not, unfortunately. Another report indicates that the MPU-401 activation is automatically enabled for Windows even on OPTi 928-based systems, which don't support it. This can be defeated by editing Windows .INI files. At least some specific versions of these boards work well with OS/2, save for wavetable support. The 929_v2.zip drivers include Windows drivers which "talk to" the OS/2 drivers, thus allowing OS/2 sounds even when running Windows programs, so long as those Windows programs aren't actually playing sounds. In practice, there may be delays of several seconds if an attempt to play from both environments occurs, however. I've received one report that, in order to use the board's CD-ROM interface, a base address of H340 must be specified on the CD-ROM driver line, and another report that H320 is the "magic" address, so users may need to fiddle with this. I've received one report of a problem with a 929-based board and a "CH-498B" motherboard's AMI BIOS "Extended RAM Area" option; the default of "0:300" caused system traps, but resetting it to "DOS-1K" fixed this problem. I've seen many reports that the current OPTi drivers don't work with VTD, but one person reports success using the drivers that come from the Warp 4.0 device driver CD, so perhaps there's some trick to it or interactions with other devices or drivers. Some OPTi-based boards use the OPTi chipset in conjunction with another chipset, such as a Crystal Semiconductor chipset, and with such products it's sometimes possible to get VTD working by installing the appropriate CS drivers or the IBM "Business Audio" drivers instead of or in conjunction with the OPTi drivers. (See the section on the Acer Magic S20 for an example.) If you have a board with both the OPTi 929 and Crystal Semiconductor 4231, you may want to use OPTi's MAD16.SYS rather than CS's CWCONFIG.SYS to initialize the board, since MAD16.SYS reportedly does a better job with this combination of chipsets.
Comments (930):
This is a sound board chipset that's apparently closely related to the 928 and 929 chipsets from OPTi, but separate 930 driver files are available (MAD16 v2.02). I've received a few reports of success with boards using this chipset under OS/2, but know little else about it. I've seen one report that REMming out the TIMER0.SYS line from CONFIG.SYS allows these boards to work with VTD. Another report suggests that the TIMER0.SYS driver that comes with the OPTi drivers is the culprit, but that the TIMER0.SYS file that comes with OS/2 works fine. Therefore, backing up the Warp 4 TIMER0.SYS and using it in place of the OPTi version should work better. Note that the OPTi TIMER0.SYS is a DEVICE, while the Warp 4 TIMER0.SYS is a BASEDEV, so they require different lines in CONFIG.SYS.
Comments (931):
Relatively new (late April, 1997) OPTi drivers exist for this board, but I've yet to receive any reports of either success or failure with it. The driver supposedly supports both Warp 4.0 and VoiceType.

Copyright © 1996, 1997, Rod Smith, rodsmith@rodsbooks.com
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