Re: Petunia/Hal Chamberlin Music...

From: Larry Anderson (
Date: 1999-10-25 02:03:01

William Levak wrote:
> On Mon, 11 Oct 1999, Larry Anderson wrote:
> > **also in related news I picked up a 'petunia' board  for the PET and an
> > article on computer music by hal chamberlin,  The petunia board has a working
> > composite video circuit for the PET (will have to check it against Nick
> > Hampshire's and MICRO's to see which one is employed, if those.) and the
> > Chamberlin article essentially shows how to make the four-voice music circuit
> > used in the MTU and the Petunia music boards.
> I also have a Petunia board, but the sound section has no components.
> Could you tell me what the chips are at positions 3 and 4 and resistors 9
> thru 24?  I have used this with the original PET's without the CRTC chip.
> You can feed the output to a monitor or use a RF modulator to feed it to a
> TV.  With the later PET's with the CRTC it is necessary to change the CRTC
> parameters to be compatible with the TV.  You also have to change a
> capacitor on the Petunia to compensate for the higher scan rate.  I don't
> have that information handy now.  I will have to dig it out.
Ok finally scanned the circuit into a GIF, here it is at:

It should be no problem to figure out what goes where...

BTW...  Anyone have any software for the Hal Chamberlin, MTU, Petunia music
board???  I have the example in the article but I am hoping to locate an editor...
01000011 01001111 01001101 01001101 01001111 01000100 01001111 01010010 01000101
  Larry Anderson - Sysop of Silicon Realms BBS  (209) 754-1363  300-2400 baud
      Commodore 8-bit page at:
01000011 01001111 01001101 01010000 01010101 01010100 01000101 01010010 01010011
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