On Tue, 16 Dec 1997 21:59:36 -0500 Chris Eddy writes: >There ain't many offerings in the old 1200 bps area, though, and if >anyone knows >of other bell 202 or V.21 products, I would love to hear of it. The calling-number delivery ("caller ID") standard uses 202 tones, so several receive-only chips are out there. One of the Motorola units (I forget the number) works better on over-the-air data than the venerable 3105 (even with it's bias carefully adjusted). For transmitting, it's rather easy to pound out the tones directly from a PIC to a resistor tree, DAC, PWM, "magic sine", etc.