[sdiy] Parallel 8 Bit DACS?

[rsdio at sounds.wa.com]

On Dec 9, 2013, at 01:16, Jack Jackson wrote:
> Thanks for your reply. I wasn't really thinking of building  
> anything soon, the Jupiter and another project are in the pipeline  
> first. Just got interested in the technology. It seems rather neat,  
> apart from the daisy chaining of eproms (or at least that's what it  
> looks like).

Maybe we're using the term "daisy chaining" differently, but I can't  
imagine any reason why you'd want to daisy chain the EPROMs  
themselves. Are you thinking that your samples will be too long for a  
single EPROM? With today's large EPROM sizes, I doubt you'll need  
more than one per voice.

The counters might certainly need to be daisy-chained if you need  
more address bits than a single counter chip can provide. The only  
other solution is to use an FPGA where you can build up the counter  
of the size that you need, but then they're just single-bit toggles  
that are daisy-chained for the address bus width.

You certainly want a separate counter and EPROM per voice, unless  
you're really clever with multiplexing.


> How would one go about interpreting linn drum binaries to work on  
> linear DACs?

Who has schematics for the Linn drum machines? That would hold most  
of the clues to binary interpretation.

Wasn't there a thread recently on Analogue Heaven or Synth DIY about  
interpreting some drum machine ROM format? I can't remember the  
model, but somebody put a lot of work into it.

Brian Willoughby
Sound Consulting