Path: utzoo!attcan!uunet!know!zaphod.mps.ohio-state.edu!wuarchive!udel!haven!adm!cmcl2!phri!cooper!gene From: gene@cooper.cooper.EDU (Gene (the Spook) ) Newsgroups: sci.electronics Subject: Re: Programmable Multi-Tone generator wanted Message-ID: <3066@cooper.cooper.EDU> Date: 15 Nov 90 02:35:06 GMT References: Organization: The Cooper Union (NY, NY) Lines: 36 in article , jon_sree@world.std.com (Jon Sreekanth) says: > In article <15621@slice.ooc.uva.nl> ropg@ooc.uva.nl (Rop Gonggrijp) writes: > > > For a phone switch I am currently developing I am looking for a chip that: > > Will generate two sine-wave tones simultaneously > > Is computer programmable (height of tones, and preferebly amplitude) > > Works from 100 to 3000 Hz The best I've seen for what you describe is the AY-3-8910 from General Instruments. This little bugger will generate up to three independent outputs whose volumes are adjustable on a log scale, variable frequency (just specify the divider of the clock reference), and can have added effects such as white noise, etc. Radio Shack used to sell it, but I'm pretty sure that a GI representative will be able to get you one, as well as literature and/or a whole databook. From what I remember, it was pretty cheap (<10bux). All CMOS, functions from hell, cheap... you can't go wrong. BTW, there were other numbers which were just as functional, such as the -8911, -912, and -8914. The -8910 has two 8-bit I/O ports which are very handy if you don't want to throw on a PIO device, but the other chips I mentioned have variations on the ports. (1 or none, for example) Here's the hitch, you pretty much need a microprocessor to program the bugger, unless you want to use any parallel port to read/write from the chip. Again, call GI and get the info. Find out if it's what you can use. Spookfully yours, Gene