Last week I attended DSO High School in New York, and spent a lot of time talking with Jim Allard, DSO's bassist. At his bass seminar he told us about a pedal he uses to get his '84-esque tone. It's the Infanem Compact Faye Sing. It's a phaser, but it has a manual mode where you can freeze the sweep of the phasing. It gives a really neat tone, close to that of Phil in the 80's. I'll post a video or a sound clip once I get my recording software working.
In the meantime here's a bass solo by Jim Allard, using the pedal: