osh@mtuxo.UUCP (d.oshinsky) (01/22/87)
***
I would like to stimulate a discussion regarding add-on hardware
for personal computers which allows for acquisition and processing of
digitized audio (note: this does not include MIDI interface boards).
Such add-on hardware should have the following characteristics:
* designed for use with a personal computer such as AT&T PC6300 and
compatibles (including the IBM PC :-), Commodore Amiga, Atari ST,
Apple Mac, etc.
* includes A/D and D/A with at least 12 bits of resolution.
14 or 16 bits would be preferable.
* the hardware should be able to sustain a sampling rate of
at least 30 kHz. 40 kHz or more would be preferable.
* may or may not include a digital signal processing chip.
(i.e., processing may be done by uP in PC, or by coprocessor)
To get the discussion rolling, I've included a description below of a
plug-in digital signal acquisition and processing board for the AT&T PC6300
and compatibles.
Dalanco Spry Signal Processor for IBM PCs
(condensed from Computer Music Journal):
The Model 10 digital signal processor from Dalanco Spry is a coprocessor
board for the IBM PC/AT/XT and compatibles. It features the 16/32 bit
TI TMS 32010 DSP chip. The TMS 32010 is a fixed point uP that computes
at 400 nsec for a multiply-accumulate operation and 60 msec for a 1024 point
complex FFT. An IEEE-standard single precision floating point multiply
takes 8.6 usec on the Model 10. Other features include three 16 bit
timers to provide sampling rates ranging from 0.001 Hz to 200 kHz, and a
2-way 16 bit register for communications between the TMS and the IBM's CPU.
Four kwords of dual-ported RAM and mutual interrupt capability between
the 2 processors is provided. Software included with the system includes
an inline assembler, a disassembler, a debugger, signal display software
and other applications examples. An external I/O connector permits the
addition of custom "piggyback" boards of various functions to be
integrated with the system. This could be used for interfacing the
device to other equipment. An upgrade from a 20 MHz version to a 25 MHz
version is available as an option.
The Model 10 costs $850 with onboard 12 bit 40 kHz A/D and D/A conversion.
Contact: Dalanco Spry, Suite 241, 2900 Connecticut Ave. NW,
Washington, DC 20008. Telephone (202) 232-7999.
David Oshinsky
{ihnp4|houxm|vax135}!mtuxo!osh
P.S. If you have comments, questions, or further information to
contribute, please send e-mail to the above address. If this posting
generates enough interest, I'll summarize to the net.
P.P.S. I have no connection whatsoever with Dalanco Spry. I have not
actually used their Model 10 DSP board and therefore cannot guarantee
that it meets the specifications given above.dillon@CORY.BERKELEY.EDU (Matt Dillon) (01/23/87)
30Khz @ 14 bits? Maybe for music, but that kind of resolution is wasted on simple voice. 8Khz @ 8 bits gives you almost undistinguishable voice replay. (With the addum that the circuit must be completely shielded and properly designed to avoid noise. But since this is an absolute requirement for 14 bits anyway, it doesn't detract at all from my point). Generally, ADCPM encoding (a sort-of delta encoding) is used to compact the data: VOICE (delta encoding of bits, not nec. ADCPM) BITS RESULT 1 character only 2 badly garbled 3 barely understood 4 understood quite well, but obviously synthesized 5 somewhat better 6 even better 7 almost indistinguishable from tape 8+ indistinguishable from tape ------------- As far as music is concerned, your now talking 12 bits @ 60Khz to get CD sound (though I would like to point at the even CD's have their failings in the higher frequency ranges). I have no idea what kind of data compaction is employed by sound-cd's. (P.S. I haven't looked at the specs for CD's recently, so I may be incorrect in my specifications here). -Matt
bill@videovax.UUCP (01/23/87)
In article <2449@mtuxo.UUCP> osh@mtuxo.UUCP (d.oshinsky) writes: >I would like to stimulate a discussion regarding add-on hardware >for personal computers which allows for acquisition and processing of >digitized audio (note: this does not include MIDI interface boards). >Such add-on hardware should have the following characteristics: > > * designed for use with a personal computer such as AT&T PC6300 and > compatibles (including the IBM PC :-), Commodore Amiga, Atari ST, > Apple Mac, etc. > > * includes A/D and D/A with at least 12 bits of resolution. > 14 or 16 bits would be preferable. > > * the hardware should be able to sustain a sampling rate of > at least 30 kHz. 40 kHz or more would be preferable. > > * may or may not include a digital signal processing chip. > (i.e., processing may be done by uP in PC, or by coprocessor) I have a pamphlet from Ariel Corp. on their DSP-16 "Real-Time Data Acquisition Processor" for the IBM PC/XT/AT. Its specs are: I/O: 16 bit linear PCM, 2 channels. Max. sample rate: 50KHz. Electronically balanced inputs with infinitely variable gain & offset. All connections via mini-stereo jacks. Anti-alias filters a 3-pole Tschbyschev with a rolloff at 20 KHz. Analog: Typical dynamic range: 85 dB. THD: 0.08%. Frequency response at 50 KHz sample rate: DC - 16 KHz +/- 0.5 dB. Digital: 5 MHz TMS 32020 (user programmable) with 32K bytes of no wait-state RAM, configurable as data and/or program memory. 256K words or 1M word (optional) dynamic buffer RAM, giving recording times of 5.25 and 21 seconds, respectively, at maximum sample rate. Sample rate adjustable from 5 to 50 KHz. Software: Comes with an assembly language driver with interfaces to many languages (e.g., BASIC, C, Pascal, FORTRAN, Macro Assembler). Also comes with 6 applications programs: Data Acquisition, Digital Audio Effects, Digital Storage Oscilloscope, Audio Loop Editor, Waveform Synthesizer, Program Development System. Other: Uses a full-size expansion slot and derives its power from the host computer (2.2 amps). Analog supplies are derived on-board. I can get more specific if anyone wants to know. I do not have pricing and availability information, but can give you the address of the company. DISCLAIMER: The above specs were paraphrased from the manufacturer's literature. I have not seen or used this product and have no connection with Ariel Corporation. -- Bill McFadden Tektronix, Inc. P.O. Box 500 MS 58-639 Beaverton, OR 97077 UUCP: ...{ucbvax,ihnp4,uw-beaver,decvax}!tektronix!videovax!bill GTE: (503) 627-6920 "How can I prove I am not crazy to people who are?"