🚀 go-pugleaf

In article <1992Sep30.231818.26069@leland.Stanford.EDU> sadman@cccrma.Stanford.EDU (Stephen A.  
Davis) writes:
>In article <1992Sep30.203344.10597@pixar.com> Bruce@Pixar.com (Bruce Perens)  
>writes:
>> Well, they may still have some purpose for real-time sound manipulation,
>> but it is _so_ hard to justify a DSP when the main processor can process
>> signals faster! That's why the NeXT is the last of the modern workstations
>> to incorporate them.

>Interesting point since the NeXT was the _first_ modern workstation to  
>incorporate a DSP.  But as long as NeXT is using some version of the 680X0  
>architecture, a DSP is a great benefit for real-time processing of any kind.   
>Especially since mach/unix is _not_ a real-time friendly OS.

Right.

And SGI Indigo is the second?  But the difference is that there is no
DSP port on Indigo, which substantially limits its usufullness.
If you put a kind of load needed to send and receive mega bits/sec of
data onto the main CPU, the supposedly fast computer won't be fast
any more.  Just find out how much the stupid RS232 serial port drains
the CPU time on NeXT even at the low speed of 19.2kbaud.

The value of DSP is not in its MIPS rating.  It is in being a superb
serial I/O processor.  Besides music synthesis, it's main function
is becoming the handling of fast serial I/O: for ISDN, very fast TTY
port(TTYDSP), sound recording, and data acquisition and reduction. 
My DSP gets interrupted 150,000 times per second with each sample
being 12 or 16 bits, and 68040 doesn't even notice this unless
something interesting happens in the input samples.  NeXT is the
only workstation that can do this now without the addition of an
expensive plug-in board.     

While I understand that not everybody needs the DSP, you should not
be viewing it as something that is meant to perform a lot of
computation.  It's an I/O peripheral interface, and a damn flexible
one at that. 

I hope that all NeXTs will always have the capability to have a DSP
or two, even if it gets dropped from the base configuration.

Current NeXTstation line has no expansion capability that directly
gets to the bus.  It would be great if stations sport one or two
tiny card slots as found on some SparcStations.

--
Izumi Ohzawa             [ $BBg_78^=;(J ]
USMail: University of California, 360 Minor Hall, Berkeley, CA 94720
Telephone: (510) 642-6440     Fax:  (510) 642-6341
Internet: izumi@pinoko.berkeley.edu (NeXT Mail OK)