zazula@uazhe0.physics.arizona.edu (RALPH ZAZULA) (02/06/91)
I expect to get my '030 cube from Bland within the next 2 weeks and the first project I am gearing up for (besides installing my HD) is building a 16-bit, dual-channel, 50KHz bandwidth, A/D converter for use with the DSP chip (primarily - audio recording). What I need to know is : is the basic documentation that comes with the NeXT enough to tell me how to interface with the DSP "C" port? I need to know what signals are required to send data to the DSP. I thought I saw somewhere that the DSP port has a similar protocoll as RS-232 or something? Is that right? I saw postings saying that the NeXT Technical Docs. weren't being shipped yet. Is there any other source for info on the 56001? Thanks, Ralph Zazula P.S. if anyone is intersted, I'm using a 100KHz f_s(max) dual 18-bit A/D chip with SNR 90dB, on-chip S/H, automatic linearity error correction, guaranteed linearity accuracy of 15 bits...... (quite a slick chip, if you ask me!) |----------------------------------------------------------------------| | Ralph Zazula "Computer Addict!" | | University of Arizona --- Department of Physics | | UAZHEP::ZAZULA (DecNet/HEPNet) | | zazula@uazhe0.physics.arizona.edu (Internet) | |----------------------------------------------------------------------| | "You can twist perceptions, reality won't budge." - Neil Peart | |----------------------------------------------------------------------|
cyliao@eng.umd.edu (Chun-Yao Liao) (02/21/91)
For your information about A/D converters, here goes a list of "good" ones To save time, I will only list those 16 bits and up ADC Micro Networks (508) 852-5400 True 16-bit A/D combines allfunctions in single package. MN6400, self-calibrate, sampling up to 50 KHz true 16 bits sampling even in extended temperature range applications. It combines an inherent track and hold function, analog input buffer, reference, clock and control logic circuitry, ad a paralel data-bus driver in a single package. 88db SNR, -98db harmonic sampling at 1kHZ full scale analog input. $175/100 Atmel Corp. (408) 441 0311 Dual 18 bit ADC uses single +5v supply AT76C120. conversion speed less tahn 10 us, input bandwidth of 50kHZ, guaranteed linearity accuracy level of 15 bits. it resolve input signals of less than 10 uV. 86 to 90 db SNR. on chip sample-and hold amp, auto linearity error correction. output code is serially in 2's complement $25/1000 available now UltraAnalog, Inc 415 657 2227 20 bit audio A/D (eleminates anti-aliasing filter) ADC 20048 20-bit. 128 times oversampling, noise-shaping algorithm that eliminates the need for anti-aliasing filters. 40 times improvement in differenntial linearity compared to conventional. 108 db dynamic range, frequency response flat to withing +-.05db. THD +N of -96db. Operate from +-15v and +-5v $199/100 Datel, Inc 508 339 3000 ADS930 16 bit, 500kHz. differential input and on board 16-word FIFO memory. two control pings allow users to read the memory when half full, full, or on command. -95db THD, 95db SNR +5v and +-15v, 2.1W $374 Analogic Corp 508 977 3000 ADC4355/56/57 low-noise, low-distortion 16 bit. 100 and 200 kHz 96db dynamic range, 95db SNR, -103db THD at 1kHz. +-15v and +5v $237.15/$226.75/$264.15 in quant of 100 hope these helps. -- cyliao@bagend.eng.umd.edu o Q. Who am I? @wam.umd.edu o A. A NeXTed person with "small" HD and OD @epsl.umd.edu o An Apple // guy xxxxxx@xxxxxx.xxxx.xxxxxxx.xxx o An airplane pilot (I hope)