I was recently a guest on the Upper Memory Block Podcast hangout #6, where the topic was PC sound methods and sound cards. I spoke the most when the topic hovered around the PC speaker, Gravis Ultrasound, Covox Speech Thing, and a few other pre-MIDI topics.
There’s no real structure, and the whole thing is more of a conversation than having structure :-) but if you’d like to jump right to the PC speaker, seek to the 5-minute mark.