I toggled Daisy into a Imsai 8080, probably from Dr. Dobbs. I then wrote a
music "compiler" in BASIC for my SWTPC 6800. You could enter three octives
of notes and it would generate a data table for the song. I drove the output
buffers on the parallel port. You just had to put your radio near the
computer.
These systems made so much radio interferance the FCC had to come out with
standards. I remember an FCC report the mentioned the SWTPC 6800 as one of
the offenders. (The Apple II switching power supply was a radio transmitter
that also put out 5 volts.)
In the early 1990s I used a Xilinx FPGA demo board and made a Music circuit
chip that blinked the LEDs at 1 Mhz. The one chip, battery operated board
would transmit for several feet. Being a RAM based FPGA, you could download
song after song. (I converted my music compiler from BASIC to C.)
-----------------------------------------------
Michael Holley
http://www.swtpc.com/mholley/index.html
-----------------------------------------------
----- Original Message -----
From: "Douglas Quebbeman" <dhquebbeman(a)theestopinalgroup.com>
To: <classiccmp(a)classiccmp.org>
Sent: Tuesday, November 27, 2001 7:44 AM
Subject: RE: AM radio music
If I remember
correctly, there was a machine code program
printed once to play "music" with a ZX80 using this method!
Older. Dr. Dobb's Journal, Issue #2... 8080 code, played
Daisy and something else, modulating the S-100 INT signal.
-dq