Ah, IVR is the jargon I was looking for in my original request. So I'm looking for the cheapest standalone IVR device I can find. Thanks.
Two problems: My Macintosh has less than 17 megabytes available on hard disk, and most software I've seen on that Web site doesn't run on a Macintosh in the first place.
I have no money to buy a PC, and no space here to put one even if I got one for free. Your use of "card" bothers me. It sounds like something that plugs inside a computer I don't have, not anything I can just sit next to my Macintosh and use via serial port the way I use my current SupraExpress 56 modem.
I don't need any multi-line device. I have just one phone line, and one thing I hold in my hand to talk on phone. No mailboxes here. I just need something that will protect me from ten to twenty harassing calls per day, while allowing that one or two non-harassing calls per month to ring my hand-phoneset, using a sort of touch-tone Turing test to discrimate between somebody who has a legitimate reason for contacting me from the others who are just harassing me. (And what do you call that phone-handset anyway? The thing that has a base with touch-tone pad, and a thing you hold in your hand with microphone and earspeaker?) .