Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site bonnie.UUCP
Path: utzoo!watmath!clyde!bonnie!jf4
From: jf4@bonnie.UUCP (John Fourney)
Newsgroups: net.micro.cbm
Subject: music application for the c64
Message-ID: <185@bonnie.UUCP>
Date: Tue, 14-Aug-84 22:20:10 EDT
Article-I.D.: bonnie.185
Posted: Tue Aug 14 22:20:10 1984
Date-Received: Wed, 15-Aug-84 02:05:45 EDT
Distribution: net
Organization: AT&T Bell Laboratories Whippany NJ
Lines: 45

x

I am working on some hardware and software to control an analog
synthesizer using the c64.  I want to build a monophonic sequencer
that records what I'm playing on the synth and stores and replays
the sequence.  I want this thing to work in real-time, so that
when I go from the record to the play mode, it automatically starts
to play the sequence.  Also, I want to have the sequencer synchronized
to a drum machine.

What I have come up with so far follows.  I can read the status of the
drum machine, which puts out a trigger for each "event", by using one
of the joystick ports.  The only memory-mapped address I know is joystick
B's, which is $DC00.
So I can hook up the drum machine to one
of the joystick bits, and then when I read (I'll be using machine
language) from this address, one of the bits will correspond to the
status of the drum machine.  The drum machine trigger is a transition
from +5 to ground.

Similarly, I can find out what's happening with the synth by using
another memory-mapped address.  The control voltage from the synth
will be digitized (6 bits) from an a/d converter.  I want to use
the same address to write data back through a d/a converter to the
synth.  Does anyone know if there is an address I can use without
going inside the machine, or building my own address selector?
Could someone with the anatomy book post the memory-mapped addresses
and what each controls?
Also, what is the best way to hook into the data bus?  I need
bits D0-D7 from one of the ports.  Does anyone have experience 
(sources, names, etc.) in connectors needed for the ports,
especially the
44-pin communications interface?

I would like to know what experience people have in writing
in machine language.  What type of assemblers can you recommend?

I am planning on using this with a Moog synth, but it will be
applicable to quite a few others.  Anyone else interested in this?
Any ideas or suggestions?

thanks,

John          (201) 386-4300 (work)
              (201) 678-3256 (home)