[sdiy] Using 8051 to build a synth

[phillip m gallo]

Jim,

Well a lot of AVR instr.  execute in 1 tick:

Renegades include:

PUSH / POP 
SBI/CBI
and all the   "STORE/LOAD INDIRECT".

Nice Proc that AVR.   Always wanted to use it as it was pin compatible
with '51 proc's and could execute in a '51 board with only RESET needing
a polarity change.   The early releases (where pin site compatibility
was the big deal) had lot's of errata and clock rates where fairly slow
at that time (~1996) and so i steered clear but as a mature and
interesting device i have a "back of the brain promissory note" to use
some of the  '8515's i have laying around.

regards,
p


-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl] On Behalf Of James Patchell
Sent: Wednesday, August 18, 2004 12:31 PM
To: Theo; synthplayer88 at spymac.com; Synth-Diy'
Subject: Re: [sdiy] Using 8051 to build a synth


You have to remember, however, the AVR executes one instruction per
clock, 
in general, whereas the pic and 8051 execute 1 instruction over several 
clocks...

At 05:51 PM 8/18/2004 +0200, Theo wrote:
>IMO AVR is a nice micro, nothing like a 8051 though!
>The AVR are RISK, but with plenty of opcodes to go around.
>If you plan programming in assembly, the AVR may be a good choice cause

>it is a bliss compared to PIC or 8051. One of the AVR main points is 
>the 32 registers on which instructions can operate.
>With that many registers it is possible to give often used variables
their
>own register, never push, never pull, never swap. (me like to do this
for
>midi input routines)
>Newer models come with a hardware mult too, never tried but "einfach
DSP"
>should be possible.
>Down side of the AVR is maximum clock speed, tops out at 16 Mhz or so.
>
>Cheers,
>Theo
>
>
>----- Original Message -----
>From: <synthplayer88 at spymac.com>
>To: Synth-Diy' <synth-diy at dropmix.xs4all.nl>
>Sent: Wednesday, August 18, 2004 5:04 PM
>Subject: Re: [sdiy] Using 8051 to build a synth
>
>
> >
> >
> > On Mon Aug 16  7:52 , 'Paul Maddox' <P.Maddox at signal.qinetiq.com> 
> > sent:
> >
> > >Hi,
> > >
> > >> I was wondering if anyone could direct me to a source/schematic 
> > >> that
>uses
> > >a 8051
> > >> as a OSC and a VCA plus envelope generator?
> > >
> > >ambitious...
> > >Why not use something faster like one of the AVRs, these are 8051 
> > >based,
>but
> > >much faster.
> >
> >
> > Hi Paul,
> > Thanks for the suggestions!!! :) Is there any other advantage that 
> > AVRs
>have over
> > 8051s?
> >
> >
> >
> > >> I have heard some of the old Roland synth are built on an 8051 eg

> > >> JX10
>but
> > >can
> > >> not find any schematic to see how that it done.........
> > >
> > >they may have done, but only to control the hardware, certainly not

> > >to generate and modify.
> >
> >
> > Right, don't think DSP was quite up to it back in those days? 
> > However, I
>don't
> > think my programming skill is quite up it yet by a long way to do 
> > all that
>DSP
> > stuff. Still trying to grasp the concept of Fourier Analysis ......
>breaking a
> > complex waveform down to a single sinusoidal in mathmatical terms 
> > that
>is........ :(
> >
> > So generating clock rate and control voltage using the 8051 is more 
> > of
>what I can
> > handle.....
> >
> >
> >
> > >> Also, I am very puzzled about using 8051 to create an VCA and a
>envelope
> > >> genrator. Can anyone shed a light on that?
> > >
> > >Multiplier is your VCA, the EG, well in its basic form, just an 
> > >up/down counter with start and end points.
> > >
> > >Paul
> > >
> >
> > Do you mean a seperate multiplier chip or use write the machine code

> > to
>use 8051
> > as a multiplier?
> >
> > Thanks!
> >
> > Scott
> > ---- Introducing Spymac MailPro: http://www.spymac.com/mailpro/
> >

         -Jim
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