Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!zephyr.ens.tek.com!uw-beaver!cornell!rochester!pt.cs.cmu.edu!o.gp.cs.cmu.edu!andrew.cmu.edu!rg20+ From: rg20+@andrew.cmu.edu (Rick Francis Golembiewski) Newsgroups: comp.sys.amiga.audio Subject: Re: CHEAP 16-bit STEREO sound samplers Message-ID: Date: 25 Jun 91 17:36:52 GMT References: <17787@chaph.usc.edu> <744@cronos.metaphor.com> <8674@jhunix.HCF.JHU.EDU> <91166.165734DXB132@psuvm.psu.edu>, <282.2865f3ac@intersil.uucp> Organization: Class of '92, Carnegie Mellon, Pittsburgh, PA Lines: 47 In-Reply-To: <282.2865f3ac@intersil.uucp> hamilton@intersil.uucp writes: >Why do you want 16 bits? Better, "CD-like" sound quality. OK, that means >40K+ samples/sec/channel (we want stereo, right?). Well, at a transfer >rate of 16bits*2channels*40000=160,000 bytes/sec, the parallel, serial, and >yes even mouse port is out. So now we're talking an internal autoconfig >card. I'm mainly a software guy, but wouldn't it be possable to use a SCSI interface? After all 160,000 bytes/sec is pretty slow compared to most amiga HD controllers. Also, with the data size that we're dealing with it requires a HD, so the potential market already should have the necessary controller. Of course this would make using a DSP difficult, but this was supposed to be low cost wasn't it? I would think that adding a DSP would up the cost significantly. >Additionally, people would probably like to hear the sample. So now we need >a pair of A/D converters. Finally, you need to put all this hardware >together along with some-sort of practical DMA scheme so the Amiga remains >multitasking, and also write a *lot* of software to make all this work Some very good points, it would be nice to be able to hear the sounds after they are digitized... >and be easy enough to use so that people will buy it. The hardware's not >trivial either-you need decent anti-aliasing filters for the A/Ds and D/As, >and the inside of an Amiga is a reasonably noisy place to try to get 16 bits >of accuracy (an LSB is ~30uV). Why insist that the AD & DA be inside the amiga? your going to want to have a bunch of plugs for audio in and out, so why not have a small shielded box that contains the plugs along with the noise sensative components? Granted that there is then the problem of getting all the bits to the card, but I don't think that it would be impossable (my lack of hardware knowledge is starting to show here :-) >So there's a lot more to it than a pair of 16 bit A/Ds. I'de definately say so... the software alone is a substantial project in itself, not to mention the design and building of the hardware. // Rick Golembiewski rg20+@andrew.cmu.edu \\ \\ #include stddisclaimer.h // \\ "I never respected a man who could spell" // \\ -M. Twain //