MIDI controlled SID, was flying faders, was [sdiy] keyboard resources

[Luc Van Den Bosch]

Sounds like a lot of work, maybe you should consider taking:
1 microcontroller (68hc11f1 for instance has 8 analog inputs and  a uart
serial com.port (for midi))
1 sid, and apropriate address-decoder logic
1 lcd or some led's
some pots, some buttons
1 (or more) EEPROM memory('s) to store the software and patches so that they
are not gone when you switch off power.
And offcoarse a lot of programming, but that's no diffrent ont the C64

If you'r going for the C64, I did some midi interfacing once with a 6850
ACIA on the C64's expansion port (used my C64 as a midi-cv converter for a
while) and that worked great, I still have the schemo's lying around
somewhere if you want.

Luc


> ----- Original Message -----
> From: John L Marshall <john.l.marshall at gte.net>
> To: <synth-diy at dropmix.xs4all.nl>
> Sent: Tuesday, August 28, 2001 10:45 PM
> Subject: Re: MIDI controlled SID, was flying faders, was [sdiy] keyboard
> resources
>
>
> > No! I was thinking of taking a Commodore 64 and stripping away all of
the
> > unnecessary junk. Throw out the tube, the tape, the disk, the keyboard,
> all
> > that stuff. Use the C64 as a SBC. Reprogram it with your favorite
> language.
> > It's got 64K of RAM, plenty. There are three ROM's; two 2764's (2364A)
and
> a
> > 2732 (2332A). Chomp the ROM's out and install sockets. There is lots of
> I/O.
> > Use the cassette interface with opto-isolator for MIDI. There are two
5626
> > interface chips for all of the controls that you would ever want to add.
> >
> > You could use rotary digital encoders for input and a serial LCD panel
for
> > output.
> >
> >  I suppose that the address lines could be lifted and an address buffer
> > could be added without too much pain. Keeping digital signals separate
> from
> > analog signals is necessary. Use a "common point ground".
> >
> > I once built a synthesizer using Walsh functions. Talk about noise. Keep
> the
> > digital separate from the analog.
> >
> > By the way, somewhere I have a resistor coefficient table for summing
> Walsh
> > values to the sine wave harmonic series. I will dig it up if someone is
> > interested.
> >
> >
> > ----- Original Message -----
> > From: Luc Van Den Bosch <luc.ky at pandora.be>
> > To: John L Marshall <john.l.marshall at gte.net>;
> <synth-diy at dropmix.xs4all.nl>
> > Sent: Tuesday, August 28, 2001 1:00 PM
> > Subject: Re: MIDI controlled SID, was flying faders, was [sdiy] keyboard
> > resources
> >
> >
> > > But .... the C64 has a VERY noisy output which makes it unusable in a
> > > musicians setup.
> > > I did once (about 10 years ago or so) use the C64 for making sounds,
> wrote
> > > some assembler code to play the SID from the C64 keyboard, i know what
> I'm
> > > talking about.
> > > Even connecting the ground of the C64's audio output to my mixer
system
> > put
> > > the digital noise on top of the output of the mixer.
> > > That's imho why everyone (including me) is building a dedicated single
> > board
> > > computer to control it.
> > > The SID station for instance uses latches on the adress-bus of the SID
> to
> > > minimise adress-bus noise bleeding to the SID's output while the
> > > microprocessor is adressing some other stuff (like keyboard, display).
> > > Another good reason might be that the C64 with it's disk drive and
> > > CRT-display is a rather ponderous thing to move to a gig.
> > >
> > > Luc
> > >
> > > ----- Original Message -----
> > > From: John L Marshall <john.l.marshall at gte.net>
> > > To: <synth-diy at dropmix.xs4all.nl>
> > > Sent: Tuesday, August 28, 2001 8:58 PM
> > > Subject: Re: MIDI controlled SID, was flying faders, was [sdiy]
keyboard
> > > resources
> > >
> > >
> > > > The "Commodore 64 Programmer's Reference Guide" has 25 pages
dedicated
> > to
> > > > the 6581SID.
> > > >
> > > > I am unclear as to why people are building dedicated single board
> > > computers
> > > > to control the SID. A single board computer already exists with
plenty
> > of
> > > > RAM, ROM and I/O. The processor is a popular but mature 8 bit type
and
> > it
> > > is
> > > > easy to program. This single board has enough speed and power to
> program
> > > the
> > > > 6581 in realtime.The addition of MIDI I/O has already been done. I'm
> > > talking
> > > > about the Commodore 64. Cheap and plentiful.
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: John Lamb <jlamb3 at nc.rr.com>
> > > > To: <synth-diy at dropmix.xs4all.nl>
> > > > Sent: Tuesday, August 28, 2001 12:53 PM
> > > > Subject: Re: MIDI controlled SID, was flying faders, was [sdiy]
> keyboard
> > > > resources
> > > >
> > > >
> > > > > "Andrew Martens" <amartens at interchange.ubc.ca> wrote on 8/27/01
> > 9:42:19
> > > > PM:
> > > > >
> > > > > >That reminds me, I need to get to work on my SID synth again...
> > > > > >
> > > > > >Cheers,
> > > > > >Andrew Martens
> > > > >
> > > > > I'm interested in doing something similar -- If you could point me
> > > towards
> > > > some good 6581 documentation I
> > > > > would be much obliged.
> > > > >
> > > > > Thanks
> > > > > John Lamb
> > > > >
> > > >
> > >
> > >
> >
>
>