Ah, thanks for showing me how to do it with Audio::DSP. OSS emulation is getting to be a pain on linux.

I switched to the fork-and-disk-buffer design, and it seems to work fine on two test machines. Performance was fine with locks and semaphores, so I didn't need to learn Sys V IPC. For anyone who's interested, the code is here: http://www.lightandmatter.com/scope/scope.html (Actually, if you could test it for me on your hardware, that could be helpful!)

Thanks, folks, for the help!!!

-Ben