tynor@gitpyr.UUCP (Steve Tynor) (09/28/84)
<is this *really* necessary?> Help! I'm in the final planning stages of constructing a micro-based music generation system. I'll be generating samples in software and sending them to a D/A converter. Is there anyone out there who can offer some advice and guidance with respect DACs? I'd like to use the new 512K Mac (great graphics, and you just can't beat the mouse... I know, I know, I'll wait till I see a good programing language out there.), but it's only contact with the outside world is an RS-422 serial port. My questions: 1) I'll be generating samples at 10K-40K Samples per second. I'd like to use a 14/16 bit converter, so I'll need to talk to te DAC at 160K-640K bits/sec. Can the RS-422 do it? (I'm assuming for the sake of argument that the Mac will be able to send them fast enough. I won't know for sure until I see a real C or Pascal compiler, or an assembler...) 2) The DAC will need the following features: a) fast enough conversion b) ability to talk 'serially' c) 14/16 bit conversion d) (optional) I'd like to have a stereo output. (I realize that my sample rate just doubled...)Are reasonably priced multiplexed DACs out there? e) The converted signal will have to be filtered at half the sample rate. Since I'll be varying the sample rate from time to time, it would be nice to have this cutoff frequency set from software. Is it possible to get a filter onboard the DAC? You may have gathered that I'm not very conversant with I/O. I'd appreciate any help or suggestions. Steve Tynor Georgia Institute of Technology ...{ihnp4, harpo}!gatech!gitpyr!tynor