On (01 Dec 94) [EMAIL PROTECTED] wrote... > Yes, I'm not sure whether there's any point in a 16-bit DAC on the Sam > (in any case you would then need to play samples at 30 or 40 KHz to make > proper use of it and that's pushing it a bit (you certainly couldn't do it > with the screen on). But if you do then you might as well do it properly; > no point in spoiling it by making it out of a resistor network hack.
Just because 16bit samples are used doesn't mean we'd HAVE to replay at the full replay rate! Every other sample would be adequate:) It's just one of those interfaces that *could* be done but I doubt weither there's any real point to doing it:-) >> I believe that the conventional SAM 4bit sample replay method involves >> quite a bit of overheads that the 8bit dongle method doesn't so the >> replayed sample rate would be better as well! > Perhaps you mean the "ldh,a:rrca:rrca:rrca:rrca:xorh:andl:xorh" that > you have to do in order to set the volume on both channels. It's not that > much actually, and not every program has to do it. Apart from that I can't > see any difference. Well you should compress the 16 or 8 bits into 4bits not just chop of the lsb's as the higher resolution samples might not be sampled at a high enough level and thus chopping off the lower bits without regard to the range of values present in the sample can effectivly result in less than 4bit resolution in the replayed sample data! and of course talking the sound chip into emulating a DAC *MUST* require more z80 processing time than a single OUT to a latch, though I could be wrong as I've yet to see how it's done yet;-) >> I've yet to uudecode imc's sample player and disasemble it > Don't you dare... ;-) GRIN, I will eventually, I presume you will want me to keep my opinions to myself when I finally get around to it;-) >> to see if it can be easily adapted to a real DAC port;-) > Of course it can. What's the problem? I assume that all you have to No idea what the problems are, YET. As yet I've not examined any sound-chip pseudo-DAC code;-) >> Also recently in the FidoNet BOFFINS echo was a msg describing the .WAV >> sample file format I've frozen it so IF anyone want's to experiment with >> that format I can post a copy in here:-) > Does it have advantages over any other kind? Is it compressed? I often None that I know of except it's better than RAW sample files, no compression either... > wonder why each machine has a different format (actually, the PC seems to > have at least 3 different ones). The reason for different Sample envelope formats is exactly the same as for different archive envelope formats and all the other things which all do the same job in an incompatable way... MONEY. In order to write and SELL a software package without having to pay royalties to some obscure writer elsewhere, to be able to use a compatable method, you have to design your own mutually exclusive method:-( The only reason to write these various sample players is to play existing samples on the sam, I presume you chose sun .au samples because you have access to a large quantity of that particular type... others may have a multitude of .WAV samples and others yet a different type! Eventually someone will sit down and combine all these players into a single semi-intelligent player that'll auto-identify the sample format and play it correctly regardless. That sort of util would be the package to sell with any DAC dongle made for the sam IMHO;-) Regards Johnathan. ... Pretend to spank me... I'm a pseudo masochist! -- |Fidonet: Johnathan Taylor 2:2501/307.9 |Internet: [EMAIL PROTECTED] | | Standard disclaimer: The views of this user are strictly his own.
