Took a while to figure this out, since it was not well documented (either that or I didn't look at the right place.) To load the driver for a SoundBlaster-16 card that is not PnP (such as the "virtual" sound card of a VMware virtual machine) you need a command line much like this one:
modprobe snd-sb16 port=0x220 irq=5 dma8=1 dma16=7 mpu_port=0 isapnp=0
The options can also appear in /etc/modules.conf.
