IBM Aptiva 2142-S44 sound problems with OS/2 Warp

By Intelligent Nonsense

My IBM Aptiva 2142-S44 machine came pre loaded with Windows 95. But being me, Windows had to go in favour of Warp 4. This gave several problems as Aptiva machines are not usually Warp compatible. I could not get any sound. On the motherboard are 2 CRYSTAL SEMICONDUCTOR chips. These are 4236B and 4610. I tried every type of driver that IBM had to offer without luck. I then tried every driver that CRYSTAL/CIRRUS had, also without luck. I tried to configure my MMPM2.INI file in the C:\OS2\MMOS2\ directory, still without luck. I sent e-mail's to both IBM and CRYSTAL SEMICONDUCTOR, also without result. Not to mention that I was also in contact with several OS/2 news groups.

Then I got the following from Joe Nord of CRYSTAL SEMICONDUCTOR:

Aptiva system has external amplifiers - outside Crystal Semi chip. Power to these amplifiers is controlled via distrete general purpose outputs of the CS423x chip. XCTRL-0 => Sub woofer power XCTRL-1 => Normal speaker power These pins default to OFF which on the Aptiva means "turn off the power to the amplifiers" --> Mute everything. Some would argue that the default should be "audible". How to fix: Expressly turn these bits on and all should be good. Add parms to CWAUDIO.sys /XCTRL0:1 /XCTRL1:1 Use cwos2207.zip from http://www.cirrus.com/drivers/audiodrv/os2.html

I hope this information can be of help to others in the same situation.

13 March 1999