Here’s all the information I can get on it. It’s not a custom soundcard so I would assume it’s attached to the motherboard.

Name Unimodem Half-Duplex Audio Device
Manufacturer Microsoft
Status OK
PNP Device ID MODEMWAVE\0{02E48346-99AA-45E2-8388-AFDB392481E8}
Driver c:\windows\system32\drivers\modemcsa.sys (5.1.2600.0 (xpclient.010817-1148), 15.75 KB (16,128 bytes), 4/17/2004 7:42 AM)

Name SoundMAX Integrated Digital Audio
Manufacturer Analog Devices, Inc.
Status OK
PNP Device ID PCI\VEN_8086&DEV_24C5&SUBSYS_01601028&REV_01\3&172E68DD&0&FD
I/O Port 0x0000EE00-0x0000EEFF
I/O Port 0x0000EDC0-0x0000EDFF
Memory Address 0xFEB7FA00-0xFEB7FBFF
Memory Address 0xFEB7F900-0xFEB7F9FF
IRQ Channel IRQ 17
Driver c:\windows\system32\drivers\smwdm.sys (5.12.01.3910, 577.94 KB (591,808 bytes), 12/31/1979 9:00 PM)