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From: mhorne@ka7axd.WV.TEK.COM (Michael T. Horne)
Newsgroups: comp.dsp
Subject: Re: My pitch shifter for 56000
Keywords: development, system, IBM, cost
Message-ID: <4676@orca.WV.TEK.COM>
Date: 25 Sep 89 17:00:09 GMT
References: <5334@merlin.usc.edu> <1989Sep25.074206.972@ivucsb.sba.ca.us>
Sender: nobody@orca.WV.TEK.COM
Reply-To: comp.dsp
Organization: Tektronix, Inc.
Lines: 39

> compatible and I really don't need to have a stand-alone system (like yours
> with a serial port).  Does anyone out there have a 56001 system running on
> an AT platform that they built/bought for under $1K?

If you're looking for a board for the PC to experiment with (assuming you
don't want to build one yourself), you can pick up the PC-56 from Ariel.
I believe it costs $595 w/o the TI codec option (add $100 for this option).
Actually, I suspect you can buy the codec for very little money from a
distributor and save yourself the extremely overpriced option that Ariel
provides. If you're looking for `CD quality' audio, I suggest you stay
away from
the codec entirely (it is exactly that; a codec, narrow bandpass and all...).
The PC-56 has a wide socket on the board for external peripherals providing
access to the 56K's data/address bus.  I'd suggest wiring up a separate board
for acquisition, preferably external to the PC box with a separate
supply, since
the PC is loaded with RF and noisy supply lines.

If you don't want to spend that much, and you feel you can handle a wire-wrap
gun and soldering iron, I'd suggest wire-wrapping a system on a board that
drops into the PC.  I've done exactly that for a project I'm working on, and
its fairly straightforward.  If you don't expect to have/need any external
RAM (at least for a while), you can really save a lot of time and effort.  You
should be able to put together a system with 16Kx24 RAM for < $200 bucks,
perhaps < $100 in a `stripped down' version.

> Does adding a second
> pair of ADC/DAC's for stereo increase the cost/complexity a lot?

Complexity, no.  Cost, probably, depending on the quality of the ADC/DACs that
you use.  You should be able to configure two complete, good quality, 12-bit
channels (both directions) for < $50 extra.  Prices rise quickly for more bits.
I'd suggest looking at Moto's new S/D ADC (the 56ADC16) which will provide you
with clean, 16-bit input at 100KHz (and it interfaces nicely to the 56K).  If
you are planning on keeping the acquisition circuit internally within the PC,
using more than 12 bits may be moot unless you take great care in layout and
cleaning up the supply lines.

Mike