real-time audio on Macs again

Phyllis or Robert Bristow-Johnson pbjrbj at viconet.com
Wed Sep 3 01:02:14 EDT 1997


Christopher Weare wrote:
> 
> Latency on the AMIII's going direct is around 20 ms.

boy, the sigma-delta codec have less delay than that!??  don't they?  i
thought they were 128 samples delay.  in and out that should be 6 ms
going direct.

>  Atleast that is
> the lowest I can get it so far.  There is an API available for directly
> addressing the AMIII and AMII cards from digi called direct IO.  I am
> not shure about how open they are about distributing it at this point.

digi is not very nice at all (at least they weren't when peter gotcha
was prez) about distributing info on getting into their hardware. 
that's why i had to do it the hard way by disassembling the Digisystem
INIT and some of their DSP code.

it's not digi plug-in compatible but i developed a reasonably complete
DSP56K development system (has boot and application loader, host and
sample I/O system, DSP debugger, simple intro example) that talks
directly to the AM1 or AM2 hardware on the NuBus (sorry, i dunno squat
about PCI).  i thought i sent it to tom erbe and to glmrboy to post on
their web pages (maybe i oughta check that out).  it's almost identical
to the Turtle Beach Multisound/Tahiti system except it's Mac/AM
instead.  it is C and 56K asm source code (i have also hacked the MPW
ASM56000 tool into a stand alone app i case you're using neither MPW nor
Code Warrior).

anyway, if it's not on any web sites, i'll send the info if you want.

r b-j
pbjrbj at viconet.com   a.k.a.   robert at audioheads.com






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