Simple 8-bit D-A / load meter? - test-drb@ccmp.vtda.org

2 Dec 2005

If you don't need high accuracy and/or have a good selection of
resistors you can do it with one resistor per bit, each one twice the
value of the next; that was the "standard" user port interface for
generating sound and music on a PET, BTW.

mike

---------------------------Original Message ------------

Date: Thu, 1 Dec 2005 19:23:14 +0000
From: Ethan Dicks <ethan.dicks at gmail.com>

On 12/1/05, Gordon JC Pearce <gordonjcp at gjcp.net> wrote:
...
  Ethan Dicks wrote:
  ... where I thought things were, but I appear to
have lost an old file
 that described how to make a simple D-A that one could hang off of an
 8-bit I/O port to generate a voltage from approx 0 VDC to +5VDC.  Does 
 Off the top of my head, look in the top left bit of a TB303 circuit
 diagram where the 7-bit converter to generate the VCO control voltage
 is.  Googling for "tb303.gif" should bring it up. 
I did eventually find that at

http://www.hylander.us/images/schematics/roland/tb303.gif

Thanks for the hint.

-ethan